Transcriptome is a collection of mRNA transcripts in a specific physiological state which has become one of the hotspots in biological research to evaluate the genes and networks in different kinds of plants. Transcriptome sequencing technology dates back to 1964 and has nearly 60 years of history. At present, the research mainly focuses on cultivating, breeding, molecular markers, and gene mining. With the increase in oil price, woody oil production can alleviate oil demand, but there are few review articles and molecular biology studies on the transcriptome of woody oil plants. In the past few decades, woody oil plants have made great progress in the development of transcriptome sequencing and bioinformatics. In this review, we reviewed the development history of sequencing technology and the research on the transcriptome of woody oil plants, mainly introducing the germplasm resources, molecular markers, and the application of important functional genes in woody oil plants. This paper not only provides ideas for mining functional genes of oil plants but also provides a reference for molecular breeding research of woody oil plants in the future.

Transgenic Arabidopsis plants expressing a potato D200 gene encoding a hypothetical protein were subjected to salinity stress and assessed for their tolerance. The D200 Arabidopsis lines exhibited increased chlorophyll content, improved stomatal conductance, less electrolyte leakage, lower accumulation of malondialdehyde (MDA), and a higher amount of proline compared to the wild type (WT) plants under salinity stress. The gene expression analysis revealed that D200 plants accumulated a significantly higher amount of mRNA transcripts of genes encoding three major antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD). Chlorophyll a fluorescence kinetics analyses showed the D200 plants were more efficient in terms of primary photochemistry of photosystem II and performance indices. Furthermore, the quantum yields and efficiencies that represent the critical steps of photosynthetic light reactions were analyzed and it was found that D200 plants were photosynthetically more active than the WT plants under salt stress conditions. Overall, these findings suggest that the D200 gene is a potential candidate gene for developing stress-resilient crops in future.

Glandular trichomes (GTs) are one of the epidermal tissues of medicinal plants which function in the synthesis, storage, and secretion of secondary metabolites. The active ingredients of Chinese medicinal materials are mostly secondary metabolites of plants. Accordingly, it is of great research value to explore the quality of medicinal materials using the GTs of medicinal plants as the starting point. However, most of the current studies on GTs of medicinal plants are still at the simple morphological identification stage, and there are few studies on the compounds secreted by GTs and secondary metabolic processes. Here, we reviewed the literature, summarized the morphological types of medicinal plant GTs, separation and purification technology, analysis technology, and biological activities of secondary metabolites, and established a research approach to medicinal plant GTs. We hope to provide a reference for future research on GT inclusions and secondary metabolism.

The link between the MtTdp1α (tyrosyl-DNA phosphodiesterase) gene, involved in the repair of DNA topoisomerase I mediated DNA damage, and the plant defense response has been investigated in MtTdp1α-depleted Medicago truncatula transgenic lines obtained by intron-spliced hairpin RNA approach, compared to the control line (CTRL, empty vector). Reduction of cuticle permeability highlighted by chlorophyll efflux assays positively correlated with the level of MtTdp1α gene silencing. The increased cuticle thickness was confirmed by transmission electron microscopy, which revealed an apparent expansion of the epicuticular waxes deposited on the outer surface. RNA-Seq analysis, carried out in the MtTdp1α-depleted plants, revealed the different expression of resistance (R) genes, PAMP (pathogen-associated-molecular pattern) triggered immunity (PTI) genes and transcription factors (TFs) involved in the regulation of the plant defense response.

NAC (NAM, ATAF1,2, and CUC2) transcription factors play an important role in the responses of plants to various environmental stresses. To investigate the function of SlNAC1, which was found to be a member of the ATAF subfamily in tomato (Solanum lycopersicum L.) plants under heat stress conditions, transgenic tomato plants were generated using an antisense technology. After a treatment at 40 °C for 48 h, in comparison with wild-type (WT) plants, the transgenic plants were severely wilted and exhibited a lower net photosynthetic rate and a maximal photochemical efficiency of photosystem II. Moreover, the transgenic plants displayed a higher ion leakage and malondialdehyde content and a lower proline content. The content of reactive oxygen species (superoxide anion radicals and hydrogen peroxide) were higher, and activities of ascorbate peroxidase and superoxide dismutase lower in the transgenic plants than in the WT plants. The transgenic plants also exhibited a lower accumulation of the transcripts of some heat shock protein genes (Hsp70, Hsp90, sHsp17.4, and sHsp17.6). All of these results suggest that the suppression of SlNAC1 could obviously reduce heat resistance in the tomato plants, and this indicates that SlNAC1 played an important role in the thermal tolerance of the tomato plants.

Proline rich proteins (PRPs), earlier famous as animal salivary proteins, have now been proven as indispensable plant proteins. They are highly rich in proline amino acid residues at the N-terminus whereas a characteristic eight cysteine motif is located at the C-terminus. The PRPs support a number of developmental processes from germination to plant death. Under normal environmental conditions, PRP genes express customarily in different plant parts depending on the specific function to be carried out. During abiotic stresses, PRP genes exhibit an uneven pattern of transcriptional regulation depending on the time and intensity of stress. Transgenic plants overexpressing PRP genes show an enhanced tolerance to abiotic stresses. This review focuses on contemporary functions of PRPs during stresses and proposes that PRPs are involved in the regulation of free cellular proline content during stress in a well synchronized manner.

Bacterial diseases of vegetable crops cause significant losses of yield and substantially decrease food quality. For sustainable development of agriculture, it is highly important to use the most effective strategies for the protection of vegetable crops from bacterial diseases which allows the creation of resistant cultivars and their introduction in regions with an increased risk of damage by phytopathogenic bacteria. This paper reviews the most widespread bacterial diseases of tomatoes, the mechanisms of interaction of plants with phytopathogenic bacteria, and the advantages of the biotechnological strategies over traditional and marker-associated breeding for creation of the resistant tomato cultivars. The current research progress on the use of biotechnological approaches such as cell selection, genetic engineering, genome editing, and gene silencing is summarized, with a special emphasis on the advantages and limitations of these methods.

Ascorbic acid (AsA) and glutathione (GSH) contribute to defense responses under abiotic stresses. The present study explored the ascorbate-glutathione cycle and ascorbate regeneration under high concentration (30 mM) of cadmium in the tea plant (Camellia sinensis L.). The tea leaves showed speckles and necrosis from the third day of Cd treatment. The content of superoxide anion (O₂^.-) and hydrogen peroxide (H₂O₂) in the leaves were significantly higher until the seventh day after Cd treatment. The content of O₂^.- and H₂O₂ were the highest on the fifth day (212.7 and 153.6 % of the control, respectively). The AsA content increased (86.9 %) on the first day after Cd treatment and decreased significantly in the subsequent days, while GSH showed a reverse trend. The enzymatic activity assays showed that dehydroascorbate reductase (DHAR) and glutathione reductase (GR) involved in AsA regeneration were downregulated considerably after Cd foliar application. In contrast, the activities of ascorbate peroxidase (APX) and monodehydroascorbate reductase (MDHAR) increased on the first day and then declined. Reverse-transcription quantitative PCR showed upregulation of glutathione synthetase (CsGSHS), γ-glutamylcysteine synthetase (Csγ-ECS), and CsMDHAR of the AsA regeneration pathway and downregulation of CsDHAR and CsGR. The expressions of GDP-L-galactose phosphorylase (CsGGP), L-galactose-1-phosphate phosphatase (CsGPP), and L-galactono- 1,4-lactone dehydrogenase (CsGaILDH) of the L-galactose pathway were also downregulated. The results indicated that AsA, which can respond to Cd stress of plants by increasing antioxidant ability, was consumed to scavenge ROS; moreover, Cd stress inhibited AsA synthesis and regeneration, which made that tea plants suffering severe damage.

Medicinal plants are a rich source of secondary metabolites, extensively used in traditional health care systems. High altitude biodiversity encompasses the diversified and valuable medicinal plant species. The extreme environmental conditions of high altitude region viz. fluctuating temperatures, high UV radiation, salinity, low oxygen concentration, and high wind velocity limits the plant growth and distribution. Yet, how medicinal plants respond to these extreme conditions is not sufficiently understood. Therefore, addressing plant acclimation to different stresses presents an opportunity to unravel adaptive mechanism of medicinal plants along altitude gradient. This article reviews the recently published research that highlights the major role of proteins in plant adaptation to extreme environmental conditions. In the last few decades, climate change has made a profound impact on high altitude plants. Stress conditions alter cellular homeostasis of plants. With the advent of proteomics, it has become evident that stresses induce changes in proteome by synthesis/expression of novel stress responsive proteins. These proteins constitute a highly organized, complex network that leads to changes in the molecular, biochemical, physiological, and morphological responses of plants. Herein, we comprehensively discuss the proteomics of medicinal plants and its role in adaptation along altitude gradient. This review aims to provide impetus to current research in medicinal plants ranging from developmental to stress biology and to generate basis for genetic engineers and plant breeders to produce next-generation medicinal plants.

Two ginseng species Panax vietnamensis and Panax stipuleanatus are precious medicinal plants restricted in several Vietnam provinces. They are very limited and endangered due to degraded habitats and over-harvesting. To preserve these two species, we used eight nuclear microsatellite markers to investigate genetic variability from the nine populations with 246 individuals for these two ginseng species. Our findings showed a moderate genetic heterozygosity in two species, P. vietnamensis (H_E = 0.386) and P. stipuleanatus (H_E = 0.342). Deficiency of heterozygosity was observed in all the studied populations of P. vietnamensis and three populations of P. stipuleanatus. Some populations had high allelic richness for both species. Private alleles were determined in all the studied populations of P. vietnamensis and two P. stipuleanatus populations. Genetic differentiation was low in two ginseng species. However, habitat loss, over-utilization and over-harvesting can be the main causes of reduced genetic heterozygosity. Neighbor-joining tree and discriminant analysis of principal components detected three major genetic groups. Finally, based on our findings, we propose in situ conservation of populations with high expected heterozygosity, allelic richness, and private alleles. Seed collection should be performed for ex-situ conservation as genetic pools in the future.

The effects of copper and zinc salts on transgenic canola plants expressing rice transcription factor (TF) OsMYB4 were investigated. Transgenic plants (TPs), which showed a high OsMyb4 expression in response to either Cu or to Zn excess, were used for the current study. In leaves of TPs, the content of Cu was equal and the content of Zn was significantly higher than in non-transformed plants (NTPs). The TPs grown on an extremely high concentration of heavy metals (HMs; 150 μМ CuSO₄ or 5 000 μМ ZnSO₄) were able to survive for more than 15 d, while NTPs died after 7 - 9 d of incubation. This indicates that expression of OsMyb4 in canola plants improved their HM tolerance. The TPs tolerance to HMs was confirmed by a higher shoot biomass than that in NTPs. Excess of HMs caused oxidative stress (indicated by increase in malondialdehyde content) especially in leaves of NTPs. This data suggests a protective role of the OsMyb4 TF in oxidative stress. The HMs caused a lower decrease in activities of superoxide dismutase and guaiacol peroxidase in TPs than in NTPs. Higher tolerance of TPs to HMs was also suggested by a considerable increase in the content of low-molecular phenolic compounds, including flavonoids and anthocyanins, as well as proline (a potential antioxidant and chaperone). These data suggest that OsMYB4 may play a role as a positive regulator of phenylpropanoid pathway and proline synthesis. The created canola OsMyb4 TPs may be useful for future applications in phytoremediation of HM-polluted soils.

In this article, we present the response of Medicago truncatula Gaert. cv. Jemalong plants expressing constitutively the Dsp22 gene from Craterostigma plantagineum to water stress and rehydration. The Dsp22 gene encodes an ELIP-like protein thought to protect the chloroplast against photooxidative damage during the dehydration and rehydration. The Dsp22 transgenic homozygous M. truncatula plants showed higher amount of chlorophyll (Chl), lower Chl a/Chl b ratio and higher actual efficiency of energy conversion in photosystem 2 (Φ_PSII) after rehydration, when compared to the wild type. The combined data from the Chl a fluorescence analysis, pigment quantification and biomass accumulation showed that transgenic M. truncatula plants are able to recover from water deprivation better than wild type plants.

Flavonoids are secondary metabolites widely distributed in plants. They not only confer a wide spectrum of pigmentation to plant flowers but also protect plants from various biotic and abiotic stresses. Simultaneously, these compounds also offer health benefits to humans. Significant efforts have been made to correlate specific flavonoid production with biosynthetic pathway gene expression. Some structure genes and transcription factors that regulate the biosynthetic pathway have been identified. However, the diverse and complex control of flavonoid accumulation is still not well understood. In this mini-review, we summarized the improvement of flavonoids by genetic engineering from the aspects of flower colour, plant resistance, and benefits on the human diet. A perspective on flavonoid research in plants is provided.

Wild rice genotypes are rich in genetic diversity. This has potential to improve agronomic rice by allele mining for superior traits. Late embryogenesis abundant (LEA) proteins are often associated with desiccation tolerance and stress signalling. In the present study, a group 3 LEA gene, Wsi18 from the wild rice Oryza nivara was expressed under its own inducible promoter element in stress susceptible cultivated indica rice (cv. IR20). The resulting transgenic plants cultivated in a greenhouse showed enhanced tolerance to soil water deficit. Transgenic plants had higher grain yield, plant survival rate, and shoot relative water content compared to wild type (WT) IR20. Cell membrane stability index, proline and soluble sugar content were also greater in transgenic than WT plants under water stress. These results demonstrate the potential for improving SWS tolerance in agronomically important rice cultivar by incorporating Wsi18 gene from a wild rice O. nivara.

Transcription factors are involved in lipid metabolism, and in present study, the transcription factor WRINKLED 1 (GhWRI1) was cloned from Gossypium hirsutum L. cv. Coker 201 by reverse transcription (RT)-PCR and rapid amplification of cDNA ends. The Pro35S:WRI1 vector was constructed and transformed into upland cotton cv. Sumian 20 using the pollen tube pathway method. After PCR and Southern blot verification of the positive transgenic plants, T₂ transgenic lines derived from T₁ individuals with the insertion gene in a single copy were chosen for further dissection. Semi-quantitative and quantitative RT-PCR analyses indicated that GhWRI1 gene expression increased in transgenic plants compared with that in the wild-type. Seed lipid content increased at most transgenic plants, and at the same time, protein content decreased. Compared to the control, major agronomical traits were not affected by overexpression of GhWRI1 in transgenic plants.

Trehalose, which plays important roles in resistance to abiotic stresses and preservation of biological activity in plants, is synthesized by two key enzymes, trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP). Therefore, the expressions of the TPS and TPP genes directly affect trehalose synthesis and stress resistance of plants. In this study, CkTPS and CkTPP from Caragana korshinskii were identified, and the role of trehalose synthesis in the adaptation of this desert plant to adverse conditions was investigated. Higher CkTPS and CkTPP expressions were observed in the roots, whereas expressions were much lower in leaves and stems, and their expressions were upregulated under drought stress. Histochemical analyses showed that β-glucuronidase expression driven by the CkTPS and CkTPP promoters was strongly induced by abiotic stresses and phytohormones, such as abscisic acid, gibberellin, methyl jasmonate, and mannitol, which suggests that trehalose synthesis may be regulated by various signaling pathways. To determine the functional mechanism underlying the role of trehalose synthesis in regulating drought response in plants, CkTPS and CkTPP were introduced into Arabidopsis. Compared to wild-type (WT) plants, these transgenic plants showed higher germination rate, survival, less damage, better shoot growth, and longer roots under drought stress. Moreover, transgenic plants had a significantly higher content of proline, chlorophyll, trehalose, and activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and lower malondialdehyde (MDA) content than WT controls. Double-transgenic plants carrying CkTPS and CkTPP showed better growth and stronger drought tolerance than either single transgenic plant line. These results provide a theoretical and experimental basis for further understanding the function and regulatory mechanism of CkTPS and CkTPP, as well as the possibility of their application for improving drought tolerance in crops through genetic engineering.

Although fullerene (C₆₀) has attracted great interest as a carbon-based nanomaterial with unique properties, today, little is known about the interaction of its water-soluble derivates, including fullerenol with higher plants. Here, we investigated how fullerenol [C₆₀(OH)_22-24] affects Zea mays, as a Strategy II plant, depending on its iron status. Iron deficiency chlorosis is a common nutritional disorder affecting plants. Maize plants were grown hydroponically, either with [+Fe^II (ferrous) or +Fe^III (ferric)] or in Fe-free (-Fe^II and -Fe^III) nutrient solution and with or without a fullerenol supply. Fullerenol affected plants differently depending on their Fe status. The beneficial effects of fullerenol were observed in the Fe^II-deprived plants, including successful suppression of plant Fe-deficiency chlorosis mainly in the younger (basal and middle) region of the leaf blade. This region expressed more severe chlorosis as compared with the older (apical) region of the leaf blade. These changes were accompanied by a significant increase in leaf active Fe and lowering the root apoplastic Fe, suggesting that fullerenol may enhance Fe mobilization in the roots, helping to alleviate Fe deficiency chlorosis. By contrast, there were no observable effects in the Fe^III-deprived plants being significantly lower in the root apoplastic Fe as compared with the Fe^II-deficient plants. Additionally, fullerenol did not affect the Fe-sufficient plants, irrespective of the Fe species (Fe^III-EDTA or Fe^II-EDTA) used as Fe-sources. Our results provide new evidence for the beneficial role of Fe-fullerenol interactions in the enhancement of gramineous plant tolerance to Fe deficiency conditions, which are one of the major limiting factors for crop production all over the world.

Cold stress is one of the major limitations to crop productivity worldwide. We investigated the effects of multiple gene expression from cold tolerant Capsella bursa-pastoris in transgenic tobacco (Nicotiana tabaccum) plants. We combined CblCE53 and CbCBF into a reconstruct vector by isocaudomers. Plant overexpression of CbICE53 under the stress inducible CbCOR15b promoter and CbCBF under a constitutive promoter showed increased tolerance to both chilling and freezing temperatures in comparison to wild-type plants, according to the electrolyte leakage and relative water content. The expressions of endogenous cold-responsive genes in transgenic tobacco (NtDREB1, NtDREB3, NtERD10a and NtERD10b) were obviously upregulated under normal and low temperature conditions. These results suggest that the CbICE53 + CbCBF transgenic plants showed a much greater cold tolerance as well as no dwarfism and delayed flowering. Thus they can be considered as a potential candidate for transgenic engineering for cold tolerant tobacco.

The gene of Zinnia elegans L. coding for S-like extracellular ribonuclease (ZRNase II) was used to produce transgenic tobacco plants with an increased ribonuclease activity. The protein-coding part of ZRNase II included the signal peptide sequence so the transgenic protein was located extracellularly. The cDNA of ZRNase II was cloned under the control of 2'-promoter of the mannopine synthase (MAS 2') gene from Ti-plasmid of Agrobacterium tumefaciens. It was shown that the resultant transgenic plants had an increased ribonuclease activity of the crude extracts and the induction of MAS 2' promoter by wounding additionally increased the activity. The plants of two transforming lines characterized by different ribonuclease activities were used to analyze the transgene influence on plant resistance to tobacco mosaic virus. The plants demonstrated either absence of disease symptoms or a significant delay in their appearance, depending on the virus content in the inoculum and ribonuclease activity.

Salt stress is one of the abiotic stresses limiting the yield of crops worldwide. However, the molecular mechanisms underlying the regulation of plant response to salt stress are not completely elucidated. Ethylene response factors (ERFs) are a subfamily of the AP2 (APETALA2)/ERF transcription factor family that regulates multiple aspects of plant growth and development, and plant responses to biotic and abiotic stresses. ERF96 is one of the small ERFs that is involved in plant defense response and abscisic acid signaling in Arabidopsis. By using real time quantitative PCR, we found that the expression of ERF96 in the wild type Arabidopsis thaliana (cv. Col-0) seedlings was induced by NaCl treatment. The transgenic plants overexpressing ERF96 were more tolerant to salt stress in terms of NaCl inhibited seed germination, early seedling development, and fresh mass. Consistent with these observations, elevated expressions of some NaCl-responsive genes including responsive drought 29 (RD29A), Δ¹-pyrroline-5-carboxylate synthetase (P5CS), cold responsive 15A (COR15A), and kinase 1 (KIN1) were observed in the transgenic plants in the presence of NaCl. We also found that the Na⁺ and K⁺ content and expressions of genes related to Na⁺/K⁺ homeostasis including stelar K⁺ outward rectifier (SKOR) and potassium transport 2/3 (AKT2/3) were altered in the ERF96 transgenic plants in response to NaCl treatment. Taken together, these results showed that overexpression of ERF96 enhanced plant tolerance to salt stress, indicating that ERF96 is a positive regulator of salt tolerance in Arabidopsis.

Stilbene synthases (STS) are plant enzymes that are responsible for the biosynthesis of stilbenes, which are plant phenolic compounds with valuable biological properties. Stilbenes also play important roles in plant tolerance to biotic and abiotic stresses. Therefore, plants that overexpress STS genes can be more resistant to various stresses. This paper investigated the effects of STS gene overexpression in Arabidopsis thaliana (L.) Heynh. Columbia-0 plants on stilbene content and tolerance to the following abiotic stresses: low and high temperatures, salinity, drought, and ultraviolet irradiation (UV-B and UV-C). We used VaSTS1 and VaSTS7 genes from grapevine (Vitis amurensis Rupr.) expressed under the double cauliflower mosaic virus 35S (CaMV35S) promoter. This study firstly demonstrated that overexpression of the VaSTS1 and VaSTS7 genes in A. thaliana plants considerably increased plant tolerance to UV-B and UV-C, while the tolerance to the low and high temperatures, salinity, and drought was not affected. We showed that the highest trans-piceid and trans-resveratrol total content was in ST1 A. thaliana plants that overexpressed the VaSTS1 gene in the range 8.28 - 22.66 µg g^-1(f.m.). ST7 plants that overexpressed the VaSTS7 gene showed only trans-resveratrol at 0.02 - 0.08 µg g^-1(f.m). Stilbene content and UV tolerance in transgenic A. thaliana plants correlated with STS transgene expression. STS expression, UV tolerance, and stilbene content was higher in VaSTS1 transgenic plants compared with that in VaSTS7 transgenic plants.

A plasmid and two isocaudamer systems, namely, NotI/Bsp120I and SpeI/XbaI/NheI, were used to construct a new type of multi-gene plant transformation vector system. This system included a transformation vector containing the restriction enzyme cutting sites Bsp120I and XbaI as well as a cloning vector containing the restriction enzyme cutting sites NotI, Bsp120I, SpeI, and NheI. The open reading frame of the new target genes was connected to the transformation vector. The original restriction enzyme cutting site disappeared after connecting to the isocaudamer. The plant transformation vector p096871, which contained Bacillus thuringiensis (Bt) genes Cry1Ac and Cry3A as well as p09X6, which contained mtlD, strD, betA, nhaA, and ostAB, were constructed using this vector system. Resistant plants were obtained after tobacco was transformed by two vectors via the Agrobacterium-mediated method. Detection by PCR revealed that all exogenous genes were inserted into the genome of tobacco. Real-time fluorescence quantification PCR, reverse transcription PCR, and ELISA detections were performed on five transgenic lines transformed by two Bt genes. Cry1Ac and Cry3A were inserted into the genome with a single copy to transcribe and express Bt toxins. The proposed vector system reduced the number of operational procedures and minimized the difficulty of the experiment.

The Arabidopsis heme oxygenase 1 (HY1) plays a significant role in the signal transduction of abiotic stimuli and hormonal response. To characterize the HY1 promoter, an approximately 1.8 kb of it (pHY1, -1666 to +132) and its deletion fragments (5D1, -1528 to +132; 5D2, -1109 to +132; 5D3, -688 to +132; 5D4, -169 to +132; 3D1, -1666 to +100; 3D2, -1666 to -1; and 3D3, -1666 to -170), were fused to the β-glucuronidase (GUS) reporter gene and transformed into Arabidopsis. The transgenic plants were subjected to several environmental stimuli (especially to mild salinity, iron deficiency, and mercury exposure). The results show that the region from +1 to +100 in the 5'-untranslated region were essential for HY1 basal promoter activity. The induced GUS activities under NaCl and H₂O₂ treatments were slowed down by the progressive 5' deletion (from -1666 to -688) and correlated with the reduced numbers of myeloblastosis (MYB) binding sites (MBSs; -1542, -1333, -1078, and -177). The MBS-free promoter construct 5D4 (-169 to +132), however, fully lost the inducibility. Therefore, we propose that the MBS elements existing in the HY1 promoter might be crucial for salinity-induced HY1 up-regulation in an H₂O₂-dependent fashion. Moreover, the regions from -169 to -1 and -688 to -169 were presumed as the regulatory regions of HY1 promoter in response to iron deficiency and mercury exposure, respectively.

Fructans play vital roles in enhancing plant abiotic stress tolerance by reducing oxidative damage, stabilizing cell membranes, improving the osmotic adjustment capacity, and lowering the freezing point. In this study, a sucrose: fructan-6-fructosyltransferase (6-SFT) gene involved in the synthesis of fructans was isolated from Dasypyrum villosum, Dv-6-SFT, using genomic walking and reverse transcription (RT)-PCR. Alignment of the cDNA sequence with its genomic counterpart showed that no introns were present in the Dv-6-SFT gene, and thus it differs from all other plant 6-SFTs that have been cloned previously. Sequence analysis showed that the cDNA of the Dv-6-SFT sequence comprised 2 175 bp with a 1 863 bp open reading frame, and its deduced protein comprised 620 amino acids with a predicted molecular mass of 68.47 kDa. The Dv-6-SFT gene was transferred into tobacco (Nicotiana tabacum L.) cv. W38 via Agrobacterium-mediated transformation. The screened plants were tested by PCR and semi-quantitative RT-PCR, and the transgenic plants were evaluated under drought, cold, and salt stresses. The Dv-6-SFT transgenic tobacco plants had higher resistance to drought, cold, and salt stress than the non-transgenic plants. Further analysis showed that the transgenic plant expressing Dv-6-SFT had increased content of saccharides and proline, but reduced content of malondialdehyde in leaves. The results of this study demonstrate that the Dv-6-SFT gene is a potential candidate for conferring abiotic stress tolerance in plants and it could be used in crop improvement breeding programs.

Heat shock and almost all types of stresses associated with oxidative stress are accompanied by heat shock protein (HSP) expression. HSPs are involved in refolding denatured proteins and directing unrepairable proteins for degradation. Thus, under stress conditions, HSPs help to restore cellular balance. However, in virus-infected plants, HSP70 can have both positive and negative effects because viruses usually recruit HSP70. HSP70 can promote the replication and translation of the viral genome, the formation of viral replication complexes, and the propagation of viral particles from cell to cell and throughout the plant. HSP gene silencing in various virus-host plants systems and the comparison of susceptible and resistant species have shown that HSPs70 accelerate the development of infection. Conversely, during the process known as thermotherapy, the temperature increase inhibits viral replication in some host and virus systems. The success of thermotherapy depends not only on the temperature and treatment period or duration but also on the plant species and viral strain. In this review, we discuss the ambiguous role that HSPs70 play during viral infections in plants towards weighing the balance between their positive and negative functions.

Providing sufficient food to burgeoning population from the steadily shrinking arable land seems to be very difficult in near future and is one of the foremost challenges for plant scientists. In addition, there are several biotic and abiotic stresses which frequently encounter crop plants during various stages of life cycle, resulting in considerable yield losses. Environmental stresses, including drought, flooding, salinity, temperature (both low and high), high radiation, and xenobiotics induce toxicity, membrane damage, excessive reactive oxygen species (ROS) production, reduced photosynthesis, and altered nutrient acquisition. Several indigenous defence mechanisms (physiological and molecular) are triggered in plants on exposure to environmental cues. Enhancement of resistance of crop plants to environmental stresses has been the topic of prime interest for agriculturalists and plant scientists since long. Development of water and salinity stress-tolerant crops through genetic engineering provides an avenue towards the reclamation of farmlands that have been lost due to salinity and lack of irrigation water/rainfall. Understanding the complexity of stress tolerance mechanisms in orthodox or model plants at the genetic and molecular levels improves feasibility of enhancing tolerance of sensitive crop plants.

Crop plants are regularly exposed to an array of abiotic and biotic stresses, among them drought stress is a major environmental factor that shows adverse effects on plant growth and productivity. Because of this these factors are considered as hazardous for crop production. Drought stress elicits a plethora of responses in plants resulting in strict amendments in physiological, biochemical, and molecular processes. Photosynthesis is the most fundamental physiological process affected by drought due to a reduction in the CO₂ assimilation rate and disruption of primary photosynthetic reactions and pigments. Drought also expedites the generation of reactive oxygen species (ROS), triggering a cascade of antioxidative defense mechanisms, and affects many other metabolic processes as well as affecting gene expression. Details of the drought stress-induced changes, particularly in crop plants, are discussed in this review, with the major points: 1) leaf water potentials and water use efficiency in plants under drought stress; 2) increased production of ROS under drought leading to oxidative stress in plants and the role of ROS as signaling molecules; 3) molecular responses that lead to the enhanced expression of stress-inducible genes; 4) the decrease in photosynthesis leading to the decreased amount of assimilates, growth, and yield; 5) the antioxidant defense mechanisms comprising of enzymatic and non-enzymatic antioxidants and the other protective mechanisms; 6) progress made in identifying the drought stress tolerance mechanisms; 7) the production of transgenic crop plants with enhanced tolerance to drought stress.

This study aimed to develop a new vector system to remove selection genes and to introduce two or more genes of interest into plants in order to express them in a coordinated manner. A multigene expression vector was established based on pCamBIA2300 using a selectable marker gene (SMG)-free system based on the combination of the isocaudamer technique and double T-DNA. The vector DT7 containing seven target genes was constructed and introduced into tobacco using Agrobacterium-mediated transformation. Twenty-one of 27 positive transgenic plants contained both T-DNA regions. The co-transformation frequency was 77.8 %. The frequency of unlinked integration of two intact T-DNAs was 22.22 % (6/27). The frequency of removal of SMG from transgenic T1 plants was 19.10 %. These results suggest that this vector system was functional and effective for multigene expression and SMG-free transgenic plant cultivation. At least seven target genes can be co-expressed using this system. Overall, these findings provide a new and highly effective platform for multigene and marker-free transgenic plant production.

Agarwood, the resin part of Aquilaria spp., is valued in medicine, perfumes, and incense. The most important components of agarwood are sesquiterpenes, which are produced only when a healthy tree is wounded. Agarwood sesquiterpene synthase 1 (ASS1) is one of key enzymes responsible for the biosynthesis of sesquiterpenes in Aquilaria sinensis (Lour.) Gilg, and it is a typical wound-inducible synthase. To elucidate its regulatory mechanism at the transcriptional level, a 978-bp sequence upstream of the translation initiation codon ATG of the promoter for ASS1 was cloned. Computational analysis revealed that this promoter contained many known cis-elements including several defense related transcriptional factor-binding boxes. To functionally validate the promoter, a 5' truncated fragment fused with the β-glucuronidase (GUS) reporter gene was used for generating stable transgenic Arabidopsis plants. The spatial and temporal expression patterns of GUS in transgenic Arabidopsis showed that the promoter of ASS1 was induced by mechanical wound and mainly expressed in vascular bundles. Subcellular localization showed that ASS1 localized in the nucleus and plasma membrane. Here, identification of the ASS1 promoter not only lays a foundation for studying its transcriptional regulation, but also provides clues for studying the synthesis mechanism of agarwood sesquiterpenes.

Vacuole membrane proteins play a critical role in the regulation of plant physiological processes including normal growth and development, and responses to stresses. The killing me slowly 1 (KMS1) gene that encodes a soluble N-ethylmaleimide-sensitive fusion attachment receptor (SNARE) domain-containing vacuole membrane protein was first reported in Arabidopsis. Currently, the function of KMS1 in other plants under stress is poorly understood. In this study, we report cloning, expression, and characterization of a novel KMS1 gene in alfalfa (Medicago sativa L.), designated MsKMS1 (GenBank accession No. JX467688). The full-length cDNA of MsKMS1 was 1 396 bp and contained a complete open reading frame of 1 257 bp, which encoded a putative protein of 418 amino acids. The BLASTp analysis showed that MsKMS1 shared high amino acid sequence similarities with KMS1 from other plants such as Medicago truncatula (99 %), Cicer arietinum (89 %), Glycine max (77 %), Prunus mume (76 %), Ricinus communis (72 %), Populus euphratica (72 %), Theobroma cacao (72 %), and Arabidopsis thaliana (67 %). Transient transformation of onion (Allium cepa) bulb scale epidermal cells by biolistic bombardment showed that MsKMS1 was localized to the plasma membrane. Quantitative real-time PCR revealed that MsKMS1 expression was upregulated under different abiotic stresses (200 mM NaCl, 20 % (m/v) polyethylene glycol 6000] and 10 mg dm^-3 abscisic acid. Transgenic tobacco plants were obtained via Agrobacterium-mediated transformation and treated with 200 mM NaCl. Reverse-transcription PCR data showed that MsKMS1 was successfully transcribed and expressed in the leaves of transgenic plants. The MsKMS1-overexpressors showed a lower malondialdehyde content and maintained a higher relative water content and proline content compared with non-transgenic controls under salt stress. These results indicate that the introduction of the MsKMS1 gene could improve salt stress resistance in tobacco plants. This study reveals the role of MsKMS1 in the regulation of plant responses to abiotic stress and provides evidence for further functional studies of the KMS1 family in alfalfa.