Modulation of Exogenous Glutathione in Phytochelatins and Photosynthetic Performance Against Cd Stress in the Two Rice Genotypes Differing in Cd Tolerance |
| |
Authors: | Yue Cai Fangbin Cao Wangda Cheng Guoping Zhang Feibo Wu |
| |
Institution: | (1) Department of Agronomy, College of Agriculture and Biotechnology, Huajiachi Campus, Zhejiang University, Hangzhou, 310029, People’s Republic of China;(2) Jiaxing Academy of Agricultural Sciences, Jiaxing, 314016, People’s Republic of China; |
| |
Abstract: | Greenhouse hydroponic experiments were conducted using Cd-sensitive (Xiushui63) and tolerant (Bing97252) rice genotypes to
evaluate genotypic differences in response of photosynthesis and phytochelatins to Cd toxicity in the presence of exogenous
glutathione (GSH). Plant height, chlorophyll content, net photosynthetic rate (Pn), and biomass decreased in 5 and 50 μM Cd
treatments, and Cd-sensitive genotype showed more severe reduction than the tolerant one. Cadmium stress caused decrease in
maximal photochemical efficiency of PSII (Fv/Fm) and effective PSII quantum yield Y(II)] and increase in quantum yield of
regulated energy dissipation Y(NPQ)], with changes in Cd-sensitive genotype being more evident. Cadmium-induced phytochelatins
(PCs), GSH, and cysteine accumulation was observed in roots of both genotypes, with markedly higher level in PCs and GSH on
day 5 in Bing97252 compared with that measured in Xiushui63. Exogenous GSH significantly alleviated growth inhibition in Xiushui63
under 5 μM Cd and in both genotypes in 50 μM Cd. External GSH significantly increased chlorophyll content, Pn, Fv/Fm, and
Y(II) of plants exposed to Cd, but decreased Y(NPQ) and the coefficient of non-photochemical quenching (qN). GSH addition
significantly increased root GSH content in plants under Cd exposure (except day 5 of 50 μM Cd) and induced up-regulation
in PCs of 5 μM-Cd-treated Bing97252 throughout the 15-day and Xiushui63 of 5-day exposure. The results suggest that genotypic
difference in the tolerance to Cd stress was positively linked to the capacity in elevation of GSH and PCs, and that alleviation
of Cd toxicity by GSH is related to significant improvement in chlorophyll content, photosynthetic performance, and root GSH
levels. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|