Authors: Huahua Wang Junjun Huang Xiaolei Liang Yurong Bi
Publish Date: 2011/08/04
Volume: 235, Issue: 1, Pages: 53-67
Abstract
The roles of ethylene hydrogen peroxide H2O2 and calcium in inducing the capacity of the alternative respiratory pathway AP under chilling temperature in Arabidopsis thaliana calli were investigated Exposure of wildtype WT calli but not the calli of ethyleneinsensitive mutants etr13 and ein21 to chilling led to a marked increase of the AP capacity and triggered a rapid ethylene emission and H2O2 generation Increasing ethylene emission by applying 1aminocyclopropane1carboxylic an ethylene precursor markedly enhanced the AP capacity in WT calli but not in etr13 and ein21 calli whereas suppressing ethylene emission by applying aminooxyacetic acid an ethylene biosynthesis inhibitor abolished the chillinginduced AP capacity in WT calli Furthermore exogenous H2O2 treatment increased the AP capacity in WT calli but not in etr13 and ein21 calli while both catalase H2O2 scavenger and diphenylene iodonium DPI an inhibitor of NADPH oxidase completely inhibited the chillinginduced H2O2 generation and largely inhibited the chillinginduced AP capacity Interestingly the chillinginduced AP capacity was completely inhibited by DPI and EGTA calcium chelator Further investigation demonstrated that H2O2 and calcium induced ethylene emission under chilling stress Ethylene modulated the chillinginduced increase of pyruvate content and the expression of alternative oxidase genes AOX1a and AOX1c Taken together these results indicate that H2O2 calcium and ethylenedependent pathways are required for chillinginduced increase in AP capacity However only ethylene is indispensable for the activation of the AP capacity
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