Glutathione transferases (GSTs) mainly catalyze the nucleophilic addition of glutathione to a large variety of hydrophobic molecules participating to the vacuole compartmentalization of many toxic compounds. In this work, the putative tolerance of transgenic tobacco plants over-expressing CsGSTU genes towards the chloroacetanilide herbicide alachlor was investigated. Our results show that the treatment with 0.0075 mg cm^-3 of alachlor strongly affects the growth of both wild type and transformed tobacco seedlings with the sole exception of the transgenic lines overexpressing CsGSTU2 isoform that are barely influenced by herbicide treatment. In order to correlate the in planta studies with enzyme properties, recombinant CsGSTs were in vitro expressed and tested for GST activity using alachlor as substrate. The recombinant GSTU2 enzyme was twice more active than GSTU1 in conjugating alachlor to GSH thus indicating that CsGSTU2 might play a crucial role in the plant defense against the herbicide. Moreover, as a consequence of the infiltration with a bacterial suspension of the P. syringae pv. tabaci, transgenic tobacco plants but not wild type plants bestowed the capability to limit toxic metabolite diffusion through plant tissues as indicated by the absence of chlorotic halos formation. Consequently, the transgenic tobacco plants described in the present study might be utilized for phytoremediation of residual xenobiotics in the environment and might represent a model for engineering plants that resist to pathogen attack.

The response of higher plants to ionising radiation depends on factors related to both radiation properties and plant features including species, cultivar, age, and structural complexity of the target organ. Adult plants of dwarf tomato were irradiated with different doses of X-rays to investigate possible variations in leaf morpho-anatomical traits, photosynthetic efficiency, and genomic DNA. In order to assess if and how responses depend on leaf developmental stage, we analysed two types of leaves; nearly mature leaves (L1) and actively developing leaves (L2), whose lamina size corresponded to 70 and 25 %, respectively, of the lamina size of the fully expanded leaves. The results show that the X-rays prevented full lamina expansion of the L2 leaves at all doses and induced early death of tissue of plants irradiated with doses higher than 20 Gy. Most anatomical modifications were not clearly dose-dependent and the radiation-induced increase in phenolic compounds was irrespective of dose. At high doses of X-rays (50 and 100 Gy), photochemical efficiency decreased significantly in both leaf types, whereas total chlorophyll content significantly decreased only in the L2 leaves. The random amplification of polymorphic DNA data show that the X-rays induced mutagenic effects in the L2 leaves even at low doses despite the absence of severe phenotypic alterations. Genetic structure found in the population of samples corroborates the results of anatomical and eco-physiological analyses: the 20 Gy dose seems to mark the threshold dose above which genetic alterations, structural anomalies, and perturbations in the photosynthetic apparatus become significant, especially in the actively expanding leaves.

Phytocyanins (PCs) are ancient blue copper-binding proteins in plants that bind to single type I copper atoms and function as electron transporters. PCs play an important role in plant development and stress resistance. Many PCs are considered to be chimeric arabinogalactan proteins (AGPs). Previously, 38, 62, and 84 PC genes were identified in Arabidopsis thaliana, Oryza sativa, and Brassica rapa, respectively. In this study, we identified 30 putative PC genes in the orchid Phalaenopsis equestris through comprehensive bioinformatics analysis. Based on phylogeny and motif constitution, the P. equestris phytocyanins (PePCs) were divided into five subclasses: 10 early nodulin-like proteins, 10 uclacyanin-like proteins, five stellacyanin-like proteins, four plantacyanin-like proteins, and one unknown protein. Structural and glycosylation predictions suggested that 16 PePCs were glycosylphosphatidylinositol-anchored proteins localized to the plasma membrane, 22 PePCs contain N-glycosylation sites, and 14 are chimeric AGPs. Phylogenetic analysis indicated that each subfamily was derived from a common ancestor before the divergence of monocot and dicot lineages and that the expansion of the PC subfamilies occurred after the divergence of orchids and Arabidopsis. The number of exons in PC genes was conserved. Expression analysis in four tissues revealed that nine PC genes were highly expressed in flowers, stems, and roots, suggesting that these genes play important roles in growth and development in P. equestris. The results of this study lay the foundation for further analysis of the functions of this gene family in plants.

The interaction between phosphorus (P) and other media components alters root development and masks the plant response and thus limits the ability to correctly identify P-deficiency response (pdr) mutants. This study aims to assess changes in root development caused by different composition of growth media normally used in Arabidopsis research and to study their effects on pdr-mutant screening. Primary root growth of four genotypes was analyzed in media differing in P concentrations: half-strength Murashige and Skoog (1/2 MS) and Somerville and Ogren (SO). The effects of nitrogen source and Fe on root growth were investigated in each medium separately and in a mixture. We found that the primary root length of all genotypes grown on 1/2 MS was reduced in comparison with plants grown on SO medium. The mutant pdr9 was the most sensitive in 1/2 MS, This mutant was also hypersensitive to Fe that intensified its sensitivity to ammonium. Ammonium increased the root inhibition caused by Fe also in wild-type plants. In conclusion, on the basis of our study we recommend to use SO medium, which ensures an efficient selection to screen for pdr mutants through root growth. Moreover, nitrogen sources in the media other than nitrate should be taken carefully.

Selenium (Se) is an essential trace element for humans and animals. A hydroponic experiment was performed to study the effects of sulphur (S) on Se uptake, translocation, and assimilation in wheat (Triticum aestivum L.) seedlings. Sulphur starvation had a positive effect on selenate uptake and the form of Se supplied greatly influenced Se speciation in plants. Compared with the control plants, Se uptake by the S-starved plants was enhanced by 4.81-fold in the selenate treatment, and selenate was readily transported from roots to shoots. By contrast, S starvation had no significant effect on selenite uptake, and selenite taken up by roots was rapidly converted to organic forms and tended to accumulate in roots. X-ray absorption near edge spectroscopy (XANES) analysis showed that organic forms of selenium, including selenocystine, Se-methyl-selenocysteine (MeSeCys), and selenomethionine-Se-oxide, were dominant in the plants exposed to selenite and accounted for approximately 90 % of the total Se. Whereas selenate remained as the dominant species in the roots and shoots exposed to selenate, with little selenate converted to selenite and MeSeCys. Besides, sulphur starvation increased the proportion of inorganic Se species in the selenate-supplied plants, but had no significant effects on Se speciation in plants exposed to selenite. The present study provides important knowledge to understand the associated mechanism of Se uptake and metabolism in plants.

Water use efficiency (WUE) is an worth attempting trait to discover the genomic regions governing it, especially in view of the diminishing water resources for the crop plants in general and rice in particular. In order to address this, the present investigation was aimed at identification of genomic regions governing WUE employing a recombinant inbred line population derived from a cross between INRC10192, a high WUE landrace, and IR64, a high yielding cultivar. A total of 36 quantitative trait loci (QTLs) were detected under control as well as drought conditions on chromosomes 1, 2, 4, 8, 9, 10, and 11. Among all, the QTLs with the marker intervals RM486-RM6703, RM6703-RM11484, RM404-RM447, RM24879-RM171, and RM229-RM332 on chromosomes 1, 8, 10, and 11 were found to govern the water use efficiency related traits such as carbon isotope discrimination, specific leaf area, leaf width, and relative water content. Nine major QTL intervals were targeted for candidate gene identification using gene ontology (GO) and transcriptome-based analyses. Overrepresented GO terms in the targeted QTLs were found to be associated with the genes/pathways controlling stomatal regulatory mechanism, stress responsive genes or transcription factors, and saccharide biosynthesis pathways under stress situation. Hence, these genes or genomic regions are potential candidates for development of high WUE rice cultivars.

Identifying important regulative elements and pathways related to dwarfism in cotton is a major challenge in cotton breeding. Isobaric tags for relative and absolute quantitation-based proteomics of stem terminal buds from upland cotton (Gossypium hirsutum L.) dwarf line LA-1 and high near-isogenic line LH-1 was performed. Moreover, transcriptional expression of differentially-expressed proteins (DEPs) belonging to phytohormone signal transduction, hormone biosynthesis, and ubiquitin system were analysed using quantitative real-time polymerase chain reaction. A total of 4 849 proteins were identified from LA-1 and LH-1, 697 of which showed differential accumulations. Most of the DEPs have catalytic, binding, and transporter activity and are involved in metabolism- and protein processing-related pathways. In particular, seven DEPs, including two gibberellin (GA) receptors, three cytokinin (CK) receptors, CKoxidase, and CK-N-glucosyltransferase were up-regulated in LA-1, and GA20-oxidase was down-regulated in LH-1. Our results suggest that the DELLA-independent GAsignalling pathway is the primary cause of dwarfism in LA-1 and indicate that CKresponse element 1-2, GA-insensitive dwarf, CKoxidase, and GA3-β-dioxygenase are potential indicators of dwarf cotton. The profiling of DEPs may offer a valuable resource for cotton breeding.

The anther culture technique, although it has been widely used in wheat breeding programs, is associated with a high albinism rate that limits its application. The mechanism of albinism has not been studied explicitly at the molecular level. In this study, differently expressed genes (DEGs) and proteins (DEPs) of albino and green seedlings from a wheat anther culture were analyzed and compared using transcriptomic sequencing (RNA-Seq), two-dimensional electrophoresis, and mass spectrometry. A total of 1 892 DEGs (1 115 down-regulated and 777 up-regulated) and 43 DEPs (15 down-regulated and 28 up-regulated) that are primarily involved in photosynthetic pathways and porphyrin and chlorophyll metabolism was identified when the albino group library was used as the control. Most DEGs participated in constructing components of thylakoids and the chloroplast envelope as determined via gene ontology analysis. The expression patterns of 12 selected genes were evaluated using real-time quantitative PCR, and the results were in agreement with the RNA-Seq analysis. Our results may assist the development of new methods to decrease the albino seedling rates in wheat anther cultures.

This study is focused on examination of crown dehydrin content during overwintering and spring dehardening periods in three Poaceae family winter plants: rye, wheat, and triticale. Frost resistances of seedlings in laboratory and field conditions were compared. Immunoblotting demonstrates that winter wheat and winter triticale differed from winter rye based on their dehydrin qualitative content. Unlike wheat and triticale, rye lacked a protein with a molecular mass of 55.3 kDa. Winter wheat contained a polypeptide with a molecular mass of 29 kDa in autumn but lacked it in winter compared with triticale. Comparison of dehydrin spectra from the three winter crops suggests a relationship between synthesis of dehydrins with molecular masses of 29 and 55.3 kDa and frost resistance of the plant species.

The effect of lanthanum on the metabolism of ascorbate (AsA) and glutathione (GSH) in the leaves of maize seedlings under cadmium stress was investigated. The findings showed that Cd remarkably increased electrolyte leakage (EL), the activities of ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase (MDHAR), glutathione reductase, L-galactono-1,4-lactone dehydrogenase, and γ-glutamylcysteine synthetase, and the content of reduced AsA, reduced GSH, total AsA, total GSH, malondialdehyde (MDA), and Cd, compared with control. However, Cd significantly decreased the dry biomass of roots and shoots. Treatment with La + Cd evidently increased the activities of above enzymes except MDHAR, the content of reduced AsA, reduced GSH, total AsA and total GSH, and the dry biomass of roots and shoots, compared with Cd stress alone. Meanwhile, treatment with La + Cd remarkably decreased EL and the content of Cd and MDA compared with Cd stress alone. Our results suggested that La could be used as a regulator to improve the Cd tolerance of maize for its role in the alleviation of Cd-induced oxidative damage by regulating the metabolism of AsA and GSH.

Multiple allele-inherited male sterility has been widely used by breeders of Brassica rapa L. ssp. pekinensis, but the molecular mechanisms of male sterility are not yet clear. In this study, we isolated the full-length cDNA of a new gene (not included in the Brassica database). This gene, comprising 1 054 bp, encodes a 39.99 kDa protein with a Gly-Asp- Ser-Leu (GDSL)-lipase domain that is a member of the lipolytic protein GDSL family. The sequence of candidate gene is the most similar to extracellular lipase 6 (EXL6) of Arabidopsis and was therefore designated BrEXL6 and submitted to NCBI (accession No. JX131630.1). Reverse transcription semi-quantitative PCR and Western blot analysis showed that BrEXL6 and its encoded protein were significantly more expressed in fertile buds than in sterile buds. Quantitative PCR and in situ hybridization showed that BrEXL6 was highly expressed in the anthers of fertile buds, especially anthers at the pollen-development stages, but only weakly expressed in other tissues and floral organs of fertile plants and whole sterile plants. These results suggest that BrEXL6 is a pollen development-related gene. The results of this study provide clues for understanding the mechanisms underlying multiple allele-inherited male sterility.

Proline is emerging as a critical component of drought tolerance and fine tuning of its metabolism under stress affects the plants sensitivity and response to stress. Thus the study was carried out to analyse the effect of water deficit on the proline content and principal enzymes involved in its synthesis (Δ¹-pyrolline-carboxylate synthetase) and catabolism (proline dehydrogenase) at different developmental stages and in different organs (roots, nodules, leaves, pod wall, and seeds) of two chickpea (Cicer arietinum L.) cultivars differing in drought tolerance (drought tolerant ICC4958 and drought sensitive ILC3279). It was observed that increased Δ¹-pyrolline-carboxylate synthetase activity under moderate stress in roots and nodules of ICC4958 caused an increase in proline content during initiation of reproductive development whereas increased proline dehydrogenase activity in nodules and leaves at this period helped to maintain reducing power and energy supply in tissues and proper seed development as seed biomass increased consistently up to maturity. On the other hand, roots and nodules of ILC3279 responded to stress by increasing proline content after the developmental phase of reproductive organs was over (near maturity) which negatively affected the response of pod wall to stress. Concurrent increase in activities of Δ¹-pyrolline-carboxylate synthetase and proline dehydrogenase in pod wall of ILC3279 aggravated the oxidative stress and affected seed development as seed biomass initially increased rapidly under stress but was unaffected near maturity.

Rice (Oryza sativa L.) is a salt-sensitive species. Salt stress can cause injury to the plant cellular membrane. Plant lipid transfer proteins (LTPs) are abundant lipid binding proteins that are important in membrane vesicle biogenesis and trafficking, however, the biological importance of LTPs on salt-stress response in rice remains unclear. Therefore, salt-responsive rice LTPs were identified and characterized in this study. Microarray analysis showed seven genes positively regulated by salinity, including five Ltp genes (LtpII.3, LtpII.5, LtpII.6, LtpV.1, and LtpV.2) and two Ltp-like (LtpL; LtpL1, and LtpL2) genes. Amino acid alignment revealed that all these Ltp and LtpL genes contained the N-terminal signal peptide. Apart from LtpL1, all salt-inducible Ltp genes had the conserved eight cysteine residue motifs backbone. Verification of gene expression to different stimuli in rice seedlings revealed that salt-regulated Ltp genes differentially responded to drought, cold, H₂O₂, abscisic acid (ABA) and CaCl₂. Furthermore, the expression of Ltp and LtpL genes was tissue-specifically regulated by ABA-dependent and independent pathway. In silico analysis of a 1.5-kb 5'-upstream region of these genes showed regulatory cis-elements associated with ABA, calcium, and cold/drought responses. Three LtpII subfamily genes, including LtpII.3, LtpII.5, and LtpII.6, were strictly expressed in flowers and seeds, and LtpIII.1 mRNA strongly accumulated in stem tissue. Subcellular localization analysis of LTP-DsRed fusion proteins revealed that the five LTPs and two LTPLs localized at the endoplasmic reticulum. The results provide new clues to further understanding the biological functions of Ltp genes.

The tonoplast and plasma membrane localized sodium (potassium)/proton antiporters have been shown to play an important role in plant resistance to salt stress. In this study, AtNHX1 and AtNHX3, two tonoplast Na⁺(K⁺)/H⁺ antiporter encoding genes from Arabidopsis thaliana, were expressed in poplar to investigate their biological functions in the resistance to abiotic stresses in woody plants. Transgenic poplar plants expressing either gene exhibited increased resistance to both salt and water-deficit stresses. Compared to the wild type (WT) plants, transgenic plants accumulated more sodium and potassium ions in the presence of 100 mM NaCl and showed reduced electrolyte leakage in the leaves under water stress. Furthermore, the proton-translocating and cation-dependent H⁺ (Na⁺/H⁺ or K⁺/H⁺) exchange activities in the tonoplast vesicles isolated from the leaves of transgenic plants were higher than in those isolated from WT plants. Therefore, constitutive expression of either AtNHX1 or AtNHX3 genetically modified the salt and water stress tolerance of transgenic poplar plants, providing a potential tool for engineering tree species with enhanced resistance to multiple abitotic stresses.

The relationship between hydrogen peroxide (H₂O₂) and nitric oxide (NO) in the regulation of ascorbate and glutathione metabolism by jasmonic acid (JA) in Agropyron cristatum leaves were studied. Results showed that JA increased the production of H₂O₂ and NO, the activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), L-galactono-1,4-lactone dehydrogenase (GalLDH), and γ-glutamylcysteine synthetase (γ-ECS), as well as transcription of the respective genes and also the content of reduced ascorbate (AsA) and reduced glutathione (GSH). Above increases were suppressed by pre-treatments with H₂O₂ synthesis inhibitor diphenylene iodonium (DPI), H₂O₂ scavenger dimethylthiourea (DMTU), NO synthesis inhibitor N ^G-nitro-L-Arg methyl ester (L-NAME), and NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO). Pre-treatments with DPI and DMTU reduced H₂O₂ and NO production. Pre-treatments with L-NAME and cPTIO reduced NO production, but did not reduce the H₂O₂ production induced by JA. Our results suggested that NO acted downstream of H₂O₂ in JA signalling in the up-regulation of ascorbate and glutathione metabolism in A. cristatum leaves.

The cucumber genes CsPDR8/CsABCG36 and CsPDR12/CsABCG40 encode two similar pleiotropic drug resistance proteins (ABCG_PDRs) belonging to the large ABC family of multispecific ATP-dependent transporters. We have already shown that the amount of root CsPDR8/CsABCG36 and CsPDR12/CsABCG40 transcripts is markedly elevated by phytohormones related to the plant response to environmental constraints, suggesting the involvement of both genes in hormone-mediated reactions to stresses. To further characterize the function and regulation of CsPDR8/CsABCG36 and CsPDR12/CsABCG40, we determined the subcellular localization of the predicted CsPDR8/CsABCG36 and CsPDR12/CsABCG40 proteins in cucumber and performed a transcriptional analysis of genes encoding these proteins under different abiotic stresses (heavy metals, salinity, osmotic stress, and oxidative stress) and redox perturbations. In addition, the activities of antioxidative enzymes as well as the content of hydrogen peroxide and superoxide were measured in cucumber roots to monitor the redox perturbations under all experimental conditions. Western blot analysis of membrane fractions prepared from cucumber roots with specific antibodies raised against the peptides corresponding to sequences unique to CsPDR8/CsABCG36 and CsPDR12/CsABCG40 revealed that both proteins localize to the plasma membrane. The transcript abundance and the plasma membrane protein content closely correlated with the stress severity and the hydrogen peroxide content but not with the superoxide anion content. Based on the results obtained so far, we may conclude that CsPDR8/CsABCG36 and CsPDR12/CsABCG40 are up-regulated under multiple stress conditions and redox perturbations and that the H₂O₂ and stress-related phytohormones can act as signaling molecules affecting the expression of both cucumber genes.

Hydroponics experiments were conducted to study the effects of sodium nitroprusside (SNP, a donor of NO) on lead toxicity in ryegrass (Lolium perenne L.) seedlings. When the ryegrass seedlings were grown in a nutrient solution containing 500 μM Pb²⁺ for two weeks, the plant biomass as well as net photosynthetic rate, transpiration rate, chlorophyll and carotenoid content of leaves decreased. The Pb stress also induced the production of superoxide anion (O₂ ^.-) and hydrogen peroxide (H₂O₂), leading to malondialdehyde (MDA) accumulation. Furthermore, the activities of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) decreased in the Pb-treated seedlings, but the catalase (CAT) activity increased. Additionally, the content of Cu in shoots and the content of K, Mg, Fe, and Zn in both shoots and roots decreased, but the content of Ca in shoots and roots increased under the Pb stress. Moreover, Pb accumulated mostly in roots, whereas a small quantity was translocated to shoots. However, the addition of 50, 100, and 200 μM SNP into the solution containing Pb increased the chlorophyll content and net photosynthetic rate, reduced Pb-induced oxidative damages, improved antioxidant enzyme activities, and inhibited translocation of Pb from roots to shoots. In particular, 100 μM SNP had the best effect on promoting growth of the ryegrass seedlings under the Pb toxicity. However, the application of 400 μM SNP had no obvious alleviating effect on Pb toxicity in the ryegrass seedlings.

The effect of a rare earth element europium (Eu) on the long-distance transport of a plant defence compound quercetin (Q) was investigated. The complex Q/Eu³⁺ was synthesized in a HEPES buffer and tested for its transport ability through Arabidopsis thaliana and its ability to interact with target molecules in plant cells. Our results show that complexation with Eu³⁺ enhanced the transport of Q through Arabidopsis roots. During the transport, the complex degraded and released a free Q to tissues where Q was originally not available. Thus, the plant became better supplied with the defensive compound Q. The obtained spectrophotometric data imply that one of the reasons for the Q/Eu³⁺ degradation was the interaction of the complex with double stranded RNAs (dsRNAs) present in Arabidopsis. Since dsRNAs are replicative forms of plant RNA viruses, the ability of Q/Eu³⁺ to release a free Q in their presence suggests further investigation of this complex as a potential antiviral agent.

Whereas microsatellite markers are well described, there are few studies investigating minisatellites. Therefore, this study aimed to identify, characterize, and validate minisatellite loci for papaya (Carica papaya L.). The entire papaya genome, which covers 330 Mb, was used to mine minisatellites with motifs ranging from 6 to 500 bp, and at least six replicates and 82 loci were validated in a set of 24 accessions. A total of 1 730 minisatellite loci were identified, located in 695 sequences, with an average of one minisatellite every 156 kb. Variation in GC content ranged from 0.00 to 83.84 % with an average of 28.84 % indicating that these papaya minisatellites are AT rich. Motifs of up to 20 bases represented 71.45 % of the markers. In addition, the observed variation in the number of motif repeats was from 6 to 186 with an average of 9.27 per minisatellite. Independent of the classification, the frequency of minisatellites decreased with an increase in the number of repeating units. Among the validated loci, 48.78 % were found to be polymorphic, and the number of alleles (N_A) ranged from two to seven with a mean of 3.10. The average polymorphic information content (PIC), expected heterozygosity (He), and observed heterozygosity (Ho) were 0.38, 0.43, and 0.11, respectively. According to genetic diversity parameters, such as NA, He, and PIC, no significant correlations were found among the size of motifs, the number of repeats, and the GC content of these minisatellites. This study clearly demonstrates the polymorphism of minisatellites and their potential use in detection of intraspecific genetic variations in C. papaya. The results will be useful when managing genetic resources and plant breeding.

PopW, a harpin protein identified from Ralstonia solanacearum, has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens. Tobacco plants transformed with popW, the PopW-encoding gene, exhibited a promoted growth rate and enhanced resistance to Tobacco mosaic virus (TMV). Here, it is documented that the transgenic tobacco plants overexpressing popW exhibited a higher resistance to R. solanacearum YN10 infection compared with that of the wild-type plants. In the popW-expressing tobacco lines, an enhanced H2O2 accumulation and hypersensitive reaction (HR) were activated in the inoculated site. In addition, the resistance was accompanied with increased transcripts in numbers of genes related to defense (including HR), reactive oxygen species (ROS) scavenging, and salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) production. These results suggest that popW acted as positive regulator in tobacco resistance against R. solanacearum via modulation of SA-, JA-, and ET-mediated signaling pathways. We report for the first time that the expression of a harpin-encoding gene in vivo improved plant resistance to R. solanacearum.

Members of the Brassicaceae family disperse their seeds through a mechanism commonly referred to as fruit dehiscence or pod shatter. Pod shatter is influenced by variations in valve margin structure and by the molecular control pathways related to valve development. Anatomical patterns of the dehiscence zone from Brassica napus L., Brassica rapa L., Brassica carinata L., and Sinapis alba L., representing fruit types differing in pod shatter resistance, were compared using histological staining. The pod shatter-susceptible plant B. napus showed an increased lignin deposition at the vascular bundle of the replum as well as an increased separation of cell layers. In pod shatter-resistant plants S. alba, B. rapa, and B. carinata, we observed two layers of lignified valve margin cells. From these four species, we isolated and identified homologs of SHATTERPROOF (SHP1, SHP2), INDEHISCENT (IND), ALCATRAZ (ALC), FRUITFULL (FUL), AGAMOUS (AG), NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1), and SEEDSTICK (STK) genes involved in fruit development and pod shatter in Arabidopsis. Transcriptional analysis of these eight genes was performed by real-time polymerase chain reaction and the results demonstrate that differences in the expression patterns of the eight genes may be associated with dehiscence variation within these four species.

Globally, drought is the main factor that reduces common bean yield. For this reason, breeding alternatives, such as molecular marker-assisted selection, that focus on various functional genes directly involved in the response to water stress, such as those encoding late embryogenesis abundant (LEA), early response to dehydration (ERD), and dehydrin proteins, have been implemented. The aim of this study was to identify differentially expressed genes of Phaseolus vulgaris in drought-tolerant cultivars Pinto Saltillo (PS) and Pinto Villa (PV), and drought-susceptible cultivars Bayo Madero (BM) and Canario 60 (C60) in vegetative and reproductive stages. Relative water content (RWC) in leaf tissue was measured. Twenty-eight P. vulgaris genes obtained from GenBank and from a subtractive suppressive library from the PS cultivar were analysed, and their expression profiles were examined by reverse transcription polymerase chain reaction (RT-PCR). Then, cDNA arrays were developed and hybridised to confirm expression which was finally validated by quantitative PCR (qPCR). The usefulness of the identified genes as selection criteria for the tolerance of different genotypes to drought was examined using cDNA arrays. Expression of 21 genes was induced by drought. The cDNA arrays confirmed that expression of 19 of these genes increased in the vegetative stage upon exposure to the drought, and a higher expression was observed in the reproductive stage compared with vegetative stage V4. Only five genes induced by the drought were found to have a lower expression in the susceptible cultivars compared with the tolerant ones. During recovery after the drought in the reproductive stage, 13 of the 21 induced genes remained transcriptionally active including LEA3 and dehydrin. The RWC during the drought in vegetative stage V4 decreased by about 55 % in all cultivars, but at the onset of flowering, it increased to 80 % in PV and PS. In contrast, in the susceptible cultivars, it remained at 55 %. Using qPCR validation, expression induction was confirmed in the drought-tolerant cultivars. Polyubiquitin2, LEA3, LEA4, and dehydrin were useful genes for selecting drought-tolerant genotypes under field conditions.

Understanding the basis of the genetic variations responsible for the complex traits found in Eucalyptus cladocalyx under arid environmental conditions is crucial for designing genetic architecture studies. Forty-five half-sib families from Australia were used to identify inter-simple sequence repeat (ISSR) markers that are associated with growth (height, diameter at breast height, and stem straightness), flowering traits (flowering intensity, flowering precocity, reproductive capacity, and late flowering) and tree survival under arid conditions in southern Atacama Desert, Chile. Each DNA pellet consisted of a pool of five trees from each family. ISSR markers were associated with all the traits studied and accounted for 9.8 to 23.4 % of the phenotypic variation. Several loci were associated with more than one trait. For example, UBC_{810(450-500 bp)}, ISO_{1(600-610 bp)}, and TGT_{9(780-800 bp)} were associated with three of the traits studied. These identified genomic regions may contribute to the increase of the efficiency of the conventional tree breeding program for E. cladocalyx.

To study the effects of application of salicylic acid (SA) on the antioxidant system and photosystem II (PS II) in wheat seedlings we used two different experiments. The first method was carried out by immersing roots in Hoagland's nutrient solution containing 0, 0.25, or 2.5 mM SA, and the second method was performed by spraying two-week-old seedlings with the same SA concentrations. After 24 h, chlorophyll fluorescence, thylakoid membrane proteins, antioxidant enzyme activities, and reactive oxygen species were measured. The low concentration of SA caused a significant increase in the antioxidant enzyme activities. However, the treatment with 2.5 mM SA resulted in an increase in the non-photochemical quenching coefficient and a decrease in the antioxidant enzyme activities, the quantum yield of PS II photochemistry, and the photochemical quenching, especially in the first method of application. All these results indicate that the effects of SA on PS II and the antioxidative defense system were dependent on the concentration used and the method of application.

Very little is known about lipid transfer proteins from flax (Linum usitatissimum L.). In the present work, three genes encoding a lipid transfer protein (LTP) were isolated from flax, two of which encoded Type-1 and one Type-2 LTPs with molecular masses of about 9 and 7 kDa, respectively. The analysis of deduced amino acid sequence reveals that only Type 2 of the L. usitatissimum leaf specific LTP (LuLTP_Ls) had an N terminal signal peptide consisting of 23 amino acids. The phylogenetic analyses of LuLTP_Ls suggest their closest relatedness with respective proteins from Dimocarpus longan and Vitis vinifera. The gene expression analysis shows that LTP Type 1 genes, which include LuLTP_Ls1 and LuLTP_Ls3, were progressively expressed during leaf development, whereas LuLTP_Ls4 (Type 2) was expressed only at initial and terminal senescence stages of cotyledons. The results suggest that both types of LuLTP_Ls were differentially yet significantly expressed in cotyledons implicating their function in transport and scavenging lipidic skeletons for the benefit of other developing parts of the plant.

Podophyllum hexandrum Royle is an important medicinal herb of North-Western Himalayas, and podophyllotoxin, being its major metabolite, has been used extensively in the preparation of several anticancer drugs. Podophyllotoxin accumulates in rhizomes; however, no information exists on the role of ATP-binding cassette (ABC) transporters vis-à-vis podophyllotoxin content. The present study reports identification, validation, and expression analysis of ABC transporter genes from P. hexandrum. Total 252 ABC transporter genes were identified as unigenes out of which 22 were further validated using real time qPCR in different tissues of varying podophyllotoxin content. Differential expression analysis and Pearson's correlation coefficient revealed two candidate genes PhABC6 and PhABCIII having a positive correlation with the podophyllotoxin content. PhABCIV showed the highest expression in rhizomes (20.53-folds compared to shoots) suggesting its possible role in transport and accumulation of podophyllotoxin.

Agricultural production worldwide has been severely impacted by cold and freezing stresses. Plant capacity to acclimate to environmental conditions in their immediate vicinity largely control their survival, growth, and productivity. Molecular as well as biochemical mechanisms underpinning plant cold acclimation are very complex and interwoven. The cold-impacted plants try to modulate expression of variety genes controlling cell membrane lipid composition, mitogen-activated protein kinase cascade, total soluble proteins, polyamines, glycinebetaine, proline, reactive oxygen species (ROS) scavengers, cryoprotectants, and a large number of cold responsive factors. To this end, this paper dissects the array of transcriptional factors/genes down- or up-regulated, their identification in different plant species, recognition of cold tolerant/resistant transgenic plants, complexity of the mitogen-activated protein kinase cascade, as well as their cross talk under different stresses and molecular mechanisms. Furthermore, it also comprehensively elucidates physio-biochemical interferences in cold acclimation with a particular emphasis on endogenous content as well as exogenously supplied different types of polyamines, ROS, and osmoprotectants. Overall, low temperature stress tolerance or cold acclimation varies greatly among species depending on the stress intensity and duration and type of plant species.

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.

The life cycle of flowering plants is partially defined by environmental cues like day length and temperature. In the model plant Arabidopsis thaliana and temperate cereals, such as barley (Hordeum vulgare) and wheat (Triticum spp.), differences in life cycle control have been associated with a natural variation in FLOWERING LOCUS C (FLC) and VERNALIZATION 1-3 (VRN1-3). In sugar beet (Beta vulgaris L.), variation in vernalization requirement and life cycle is determined by a major gene at the B locus. This gene has recently been identified as a pseudo-response regulator (PRR) gene BOLTING TIME CONTROL 1 (BTC1). A second gene in beet with homology to BTC1 and ARABIDOPSIS PSEUDO RESPONSE REGULATOR 7 (APRR7) in Arabidopsis was identified and termed Beta vulgaris PSEUDO RESPONSE REGULATOR 7 (BvPRR7). We functionally characterized BvPRR7 by transgenic analysis in Arabidopsis and expression profiling during development in beet. We show that BvPRR7 was diurnally regulated and responded to cold. Constitutive expression of BvPRR7 distorted diurnal rhythms and caused late flowering in Arabidopsis suggesting a conserved function of BvPRR7 in clock regulation. Conceivably, the retention of a functional role of BvPRR7 in clock regulation may have facilitated the evolution of a distinct role as major floral regulator of the second PRR7 homolog in beet, BTC1.