A transcriptomic analysis reveals the nature of salinity tolerance of a wheat introgression line

Abstract

The bread wheat cultivar Shanrong No.3 (SR3) is a salinity tolerant derivative of an asymmetric somatic hybrid between cultivar Jinan 177 (JN177) and tall wheatgrass (Thinopyrum ponticum). To reveal some of the mechanisms underlying its elevated abiotic stress tolerance, both SR3 and JN177 were exposed to iso-osmotic NaCl and PEG stress, and the resulting gene expression was analysed using a customized microarray. Some genes associated with stress response proved to be more highly expressed in SR3 than in JN177 in non-stressed conditions. Its unsaturated fatty acid and flavonoid synthesis ability was also enhanced, and its pentose phosphate metabolism was more active than in JN177. These alterations in part accounted for the observed shift in the homeostasis related to reactive oxygen species (ROS). The specific down-regulation of certain ion transporters after a 0.5 h exposure to 340 mM NaCl demonstrated that Na(+) uptake occurred rapidly, so that the early phase of salinity stress imposes more than simply an osmotic stress. We discussed the possible effect of the introgression of new genetic materials in wheat genome on stress tolerance.

A Wheat SIMILAR TO RCD-ONE Gene Enhances Seedling Growth and Abiotic Stress Resistance by Modulating Redox Homeostasis and Maintaining Genomic Integrity

“…Note that both of these ROS processing pathways need GSH and NAD(P)H as reducing agents, thereby reducing the GSH/GSSG and NAD(P)H/ NAD(P) + ratios ( Figures 9I to 9K). The efficient antioxidant system ensures redox homeostasis, which can be indicated by the lower malondialdehyde (MDA) content in Ta-sro1 overexpression lines of Arabidopsis under salinity (Supplemental Figure 11), in agreement with that in SR3 (Liu et al, 2012). DNA damage in protoplasts of Arabidopsis plants constitutively expressing Ta-sro1 and VC plants exposed to UV for 30 s, 60 s, and 2 min or 3 mM H 2 O 2 or 5 mM H 2 O 2 as indicated.…”

“…A set of 226 genes that were differentially expressed (by at least 2-fold) in SR3 seedlings under stress (200 mM NaCl or 18% PEG) was identified by microarray analysis (Liu et al, 2012). Out of these genes, those related to ROS homeostasis are suggested to play an important role in the generation of the above salinity-tolerant phenotype of cultivar SR3.…”

“…KClO 4 was removed by centrifugation for 15 min at 20,000g at 2°C, and the supernatant was used to determine ATP content immediately with the ENLITEN ATP assay system (Promega) according to the manufacturer's protocol. MDA content was determined according to Liu et al (2012).…”

“…This novel cultivar has been shown to be higher yielding than its wheat parent Jinan 177 (JN177) when grown in saline soil and has been planted commercially in a number of areas where the soil suffers from alkaline salinity (Xia, 2009). The genetic basis of much of its salinity tolerance has been shown to rely on ROS homeostasis based on the transcriptomic and proteomic outcomes in response to salinity stress (Peng et al, 2009;Liu et al, 2012). Here, we report the superior traits of SR3 and demonstrate that a candidate gene, which is the allele of the parent JN177 via point mutations, encodes an SRO protein containing a N-terminal WWE domain, a PARP-like domain, and a C-terminal RST domain.…”

Progress in plant protoplast research

“…Further proteome analysis indicates a better adaptation of the cybrid to cold or drought stress and an upregulated Rubisco activity (wang et al 2010). The complicated regulation mechanism between gene and protein can interfere with downstream hybrid monitoring; Liu et al (2012) demonstrated introgression on the RNA level, but found little correlation between transcriptome and proteome.…”