Ectopic Expression of GsPPCK3 and SCMRP in Medicago sativa Enhances Plant Alkaline Stress Tolerance and Methionine ContentReport as inadecuate




Ectopic Expression of GsPPCK3 and SCMRP in Medicago sativa Enhances Plant Alkaline Stress Tolerance and Methionine Content - Download this document for free, or read online. Document in PDF available to download.

So far, it has been suggested that phosphoenolpyruvate carboxylases PEPCs and PEPC kinases PPCKs fulfill several important non-photosynthetic functions. However, the biological functions of soybean PPCKs, especially in alkali stress response, are not yet well known. In previous studies, we constructed a Glycine soja transcriptional profile, and identified three PPCK genes GsPPCK1, GsPPCK2 and GsPPCK3 as potential alkali stress responsive genes. In this study, we confirmed the induced expression of GsPPCK3 under alkali stress and investigated its tissue expression specificity by using quantitative real-time PCR analysis. Then we ectopically expressed GsPPCK3 in Medicago sativa and found that GsPPCK3 overexpression improved plant alkali tolerance, as evidenced by lower levels of relative ion leakage and MDA content and higher levels of chlorophyll content and root activity. In this respect, we further co-transformed the GsPPCK3 and SCMRP genes into alfalfa, and demonstrated the increased alkali tolerance of GsPPCK3-SCMRP transgenic lines. Further investigation revealed that GsPPCK3-SCMRP co-overexpression promoted the PEPC activity, net photosynthetic rate and citric acid content of transgenic alfalfa under alkali stress. Moreover, we also observed the up-regulated expression of PEPC, CS citrate synthase, H+-ATPase and NADP-ME genes in GsPPCK3-SCMRP transgenic alfalfa under alkali stress. As expected, we demonstrated that GsPPCK3-SCMRP transgenic lines displayed higher methionine content than wild type alfalfa. Taken together, results presented in this study supported the positive role of GsPPCK3 in plant response to alkali stress, and provided an effective way to simultaneously improve plant alkaline tolerance and methionine content, at least in legume crops.



Author: Mingzhe Sun , Xiaoli Sun , Yang Zhao, Chaoyue Zhao, Huizi DuanMu, Yang Yu, Wei Ji, Yanming Zhu

Source: http://plos.srce.hr/



DOWNLOAD PDF




Related documents