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Major Progress made in HFUT Professors’ Study on Genetic Engineering in Phytorem
time: Apr 12, 2015

“MAN3 gene regulates cadmium tolerance through the glutathione-dependent pathway in Arabidopsis thaliana”with HFUT Professors from School of Biotechnology and Food Engineering as the main researchers was published on top international botanical journal New Phytologist. Professor Chen Jian and Yang Libong are the joint first authors, with Professor Cao Shuqing and Liu Yongsheng as the authors for correspondence. The study was funded by Major Program of National Genetically Modified Foundation of China and National Natural Science Foundation of China, amongst others.

Soil pollution by the heavy metal cadmium (Cd) is one of the major global environmental problems. The heavy metal in the soil can be absorbed into the food chain through crops, posing a grave threat to the food safety and human health. Genetic Engineering in Phytoremediation is one of the important approaches to tackle heavy metal pollution in soil. Nonetheless, the sticking point is to locate and discover the key genes contributing to heavy metal tolerance and accumulation and elaborate their working mechanism so as to make a success in the genetic engineering and control the safety of agricultural produce from the source.

“Here, we identified an Arabidopsis thaliana cadmium-tolerant dominant mutant xcd1-D (XVE system-induced cadmium-tolerance 1) and cloned XCD1 gene (previously called MAN3), which encodes an endo-β-mannanase. Overexpression of MAN3 led to enhanced Cd accumulation and tolerance, whereas loss-of-function of MAN3 resulted in decreased Cd accumulation and tolerance. In the presence of estradiol, enhanced Cd accumulation and tolerance in xcd1-D was associated with GSH-dependent, Cd-activated synthesis of PCs, which was correlated with coordinated activation of gene expression. Cd stress-induced expression of MAN3 and the consequently increased mannanase activity, led to increased mannose content in cell walls. Moreover, mannose treatment not only rescued the Cd-sensitive phenotype of the xcd1-2 mutant, but also improved the Cd tolerance of wild-type plants.” , as per the summary.

The study results unveil the new function of MAN3 and its induced mannose, bringing to light the GSH-dependent PC synthesis pathway for the first time, therefore providing new technical channels and genetic resources to the Genetic Engineering in Phytoremediation.