Nitric oxide exacerbates Al-induced inhibition of root elongation in rice bean by affecting cell wall and plasma membrane properties.
Aluminum (Al) toxicity is one of the most widespread problems for crop production on acid soils, and nitric oxide (NO) is a key signaling molecule involved in the mediation of various biotic and abiotic stresses in plants. Here we found that exogenous application of the NO donor sodium nitroprusside (SNP) exacerbated the inhibition of Al-induced root growth in rice bean [Vigna umbellata (Thunb.) Ohwi & Ohashi 'Jiangnan', Fabaceae]. This was accompanied by an increased accumulation of Al in the root apex. However, Al treatments had no effect on endogenous NO concentrations in root apices. These results indicate that a change in NO concentration is not the cause of Al-induced root growth inhibition and the adverse effect of SNP on Al-induced root growth inhibition should result from increased Al accumulation. Al could significantly induce citrate efflux but SNP had no effects on citrate efflux either in the absence or presence of Al. On the other hand, SNP pretreatment significantly increased Al-induced malondialdehyde accumulation and Evans Blue staining, indicating an intensification of the disruption of plasma membrane integrity. Furthermore, SNP pretreatment also caused greater induction of pectin methylesterase activity by Al, which could be the cause of the increased Al accumulation. Taken together, it is concluded that NO exacerbates Al-induced root growth inhibition by affecting cell wall and plasma membrane properties.
Key Laboratory of Conservation Biology for Endangered Wildlife, Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, China. 10614051@zju.edu.cn
Yuan
Y
Zhou
Xiao Yan
XY
Xu
Li Qian
LQ
Chen
Jian Li
JL
Yang
Shao Jian
SJ
Zheng
D000535:Aluminum / Q000494:pharmacology*; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry; D002462:Cell Membrane / Q000187:drug effects* / Q000201:enzymology; D002473:Cell Wall / Q000187:drug effects* / Q000201:enzymology; D019343:Citric Acid / Q000737:chemistry; D005070:Evans Blue / Q000737:chemistry; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000737:chemistry; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D018384:Oxidative Stress; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D013194:Staining and Labeling
D009599:Nitroprusside; D019343:Citric Acid; D009569:Nitric Oxide; D005070:Evans Blue; D008315:Malondialdehyde; D000535:Aluminum; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase