Degradation and resynthesis of chlorophyll during increased oxidative stress and prolonged darkness differ between annual and perennial flax(Linum L.)  

作　　者：Kenyon J. Nisbett Abida Alokozai Su Hyun Elizabeth Ko G. Adam Mott Jason C.L. Browna 

机构地区：[1]Department of Biological Sciences,University of Toronto Scarborough,Toronto,ON,Canada [2]Department of Cell&Systems Biology,University of Toronto,Toronto,ON,Canada [3]Centre for the Analysis of Genome Evolution&Function,University of Toronto,Toronto,ON,Canada

出　　处：《Oil Crop Science》2024年第2期121-130,共10页中国油料作物学报(英文版）

基　　金：GAM is supported by a Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant。

摘　　要：Among plants,there is considerable variation in lifespan:annuals live less than one year,whereas perennials live for several years,with the longest-living perennial having survived 43,600 years.As proposed by the Disposable Soma Theory,this lifespan variation among plants likely reflects differential investment of limited energy and nutrient resources,with perennials investing more energy and nutrients into biomolecular maintenance compared to annuals in order to ensure persistence over multiple seasons.Such differential investment may be particularly important during periods of exogenous stress,which are known to accelerate biomolecular damage.The present study evaluated this hypothesis using annual and perennial flax(Linum L.)subjected to two exogenous stressors—increased oxidative stress(i.e.,foliar H2O2spraying)and complete prolonged darkness.As chlorophyll has been shown to exhibit degradation in response to changes in environmental conditions,we utilized changes in chlorophyll levels during and after periods of exogenous stress to evaluate our hypotheses.We predicted that i)perennials would exhibit a slower rate of chlorophyll degradation during exposure to exogenous stressors compared to annuals,and ii)perennials would exhibit a faster rate of chlorophyll resynthesis following such exposure compared to annuals.Chlorophyll levels before,during,and after exposure to both exogenous stressors were measured in two separate trails,once using image colour analysis and once using spectrophotometry.While chlorophyll degradation rates in response to oxidative stress did not differ between annuals and perennials,contrary to our predictions,chlorophyll resynthesis rates following such exposure were significantly higher in perennials,as predicted.When plants were subjected to complete prolonged darkness,chlorophyll degradation rates were significantly lower in perennials than annuals,as predicted;however,when plants were subsequently reintroduced to natural photoperiod,chlorophyll resynthesis rates did not consistent

关 键 词：Ageing Life history Maximum lifespan Oxidative stress Somatic maintenance 

分 类 号：S563.2[农业科学—作物学]