Abiotic stresses such as heat, drought, and salinity are major environmental constraints that limit potato (Solanum tuberosum L.) production worldwide. Previously, we found a potential ...thermo-tolerance gene, named StnsLTP1 from potato using yeast functional screening. Here, we report the functional characterization of StnsLTP1 and its role in multiple abiotic stresses in potato plants. Computational analysis of StnsLTP1 with other plant LTPs showed eight conserved cysteine residues, and four α-helices stabilized by four disulfide bridges. Expression analysis of StnsLTP1 gene showed differential expression under heat, water-deficit and salt stresses. Transgenic potato lines over-expressing StnsLTP1 gene displayed enhanced cell membrane integrity under stress conditions, as indicated by reduced membrane lipid per-oxidation, and hydrogen peroxide content relative to untransformed (UT) control plants. In addition, transgenic lines over-expressing StLTP1 also exhibited increased antioxidant enzyme activity with enhanced accumulation of ascorbates, and up-regulation of stress-related genes including StAPX, StCAT, StSOD, StHsfA3, StHSP70, and StsHSP20 compared with the UT plants. These results suggests that StnsLTP1 transgenic plants acquired improved tolerance to multiple abiotic stresses through enhanced activation of antioxidative defense mechanisms via cyclic scavenging of reactive oxygen species and regulated expression of stress-related genes.
The present study aims to investigate the numerous factors influencing Agrobacterium tumefaciens-mediated genetic transformation of Chinese cabbage (Brassica rapa ssp. pekinensis). Factors affecting ...transformation efficiency, such as age of explants, Agrobacterium concentration, and effect of acetosyringone, pre-cultivation, infection and co-cultivation time of Agrobacterium were examined. The pre-cultured hypocotyls from young seedlings prior to exposure to Agrobacterium showed higher shoot regeneration. The plant transformation with the modest A. tumefaciens concentrations (0.8 OD) and the 3 days co-cultivation periods increased transformation efficiency. Plant growth hormones 1-naphthyl acetic acid (NAA) and 6-benzyl amino purine (BAP) were essential for callus and shoot formation. Root formation was effective in half strength MS medium without supplementation of root-inducing hormones. To maintain selection pressure, plant subculture was carried out every 2 weeks with selective antibiotics. The putative transgenic plants were acclimatized in the greenhouse. Polymerase chain reaction was performed to confirm the integration of T-DNA into the genome of transgenic plants. A transformation efficiency of 15 % was obtained. This protocol allows effective transformation and indirect regeneration of Brassica rapa.
With 1 figure and 3 tables ABSTRACT: Simple sequence repeats (SSRs) derived from expressed sequence tags (ESTs) are important resources for gene discovery and mapping. In this study, we developed ...EST‐based SSR (eSSRs) markers and assessed their ability in mapping and transferability. A total of 10 800 unigenes were detected from 18 522 pea EST sequences (December 2009). Screening of 10 800 unigenes by MISA (MIcroSAtellite) revealed 2612 (14.1%) eSSRs in 2395 (12.9%) SSR‐containing ESTs from which 577 (24.1%) primer pairs were designed. The most abundant repeat motif identified in eSSR was mononucleotide (85.2%), followed by trinucleotide (10.6%) and dinucleotide (2.8%). Among 108 randomly selected primer pairs, 40 were assessed for mapping and 68 to test cross‐species transferability in six leguminous species. Out of 40 primer pairs, 85% produced amplicons, 60% showed polymorphism and 47.5% were mapped. Furthermore, 68 primer pairs revealed high rate of transferability (48–85%) in leguminous species. High levels of polymorphism, reproducibility, presence of alleles (3.8/locus) and transferability revealed the potential use of these eSSR markers in molecular mapping, quantitative trait loci (QTL) analysis and comparative mapping in pea and other legumes.
The present study aims to investigate the numerous factors influencing
Agrobacterium tumefaciens
-mediated genetic transformation of Chinese cabbage (
Brassica rapa
ssp.
pekinensis
). Factors ...affecting transformation efficiency, such as age of explants,
Agrobacterium
concentration, and effect of acetosyringone, pre-cultivation, infection and co-cultivation time of
Agrobacterium
were examined. The pre-cultured hypocotyls from young seedlings prior to exposure to
Agrobacterium
showed higher shoot regeneration. The plant transformation with the modest
A. tumefaciens
concentrations (0.8 OD) and the 3 days co-cultivation periods increased transformation efficiency. Plant growth hormones 1-naphthyl acetic acid (NAA) and 6-benzyl amino purine (BAP) were essential for callus and shoot formation. Root formation was effective in half strength MS medium without supplementation of root-inducing hormones. To maintain selection pressure, plant subculture was carried out every 2 weeks with selective antibiotics. The putative transgenic plants were acclimatized in the greenhouse. Polymerase chain reaction was performed to confirm the integration of T-DNA into the genome of transgenic plants. A transformation efficiency of 15 % was obtained. This protocol allows effective transformation and indirect regeneration of
Brassica rapa
.
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