褪黑素对镉胁迫下蒿柳光合速率下降的缓解效应  

Alleviation effect of melatonin on degressive photosynthetic rate in Salix viminalis exposed to cadmium

作　　者：殷佳慧 李霞[3] 邹竣竹 巨关升 宁崴[2] 李奥 王元成 孙振元 YIN Jiahui;LI Xia;ZOU Junzhu;JU Guansheng;NING Wei;LI Ao;WANG Yuancheng;SUN Zhenyuan(Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration,Research Institute of Forestry,Chinese Academy of Forestry,Beijing 100091,China;Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding,College of Forestry and Grassland Science,Jilin Agricultural University,Changchun 130118,China;College of Agriculture and Bioengineering(Peony Institute),Heze University,Heze 274000,Shandong,China)

机构地区：[1]中国林业科学研究院林业研究所,国家林业局林木培育重点实验室,北京100091 [2]吉林农业大学林学与草学学院,吉林省林草遗传育种重点实验室,长春130118 [3]菏泽学院农业与生物工程学院(牡丹学院),山东菏泽274000

出　　处：《生态学杂志》2024年第11期3255-3265,共11页Chinese Journal of Ecology

基　　金：吉林省自然科学基金(联合基金项目)资助项目“基于镉污染植物修复的长白山区蒿柳资源评价及研究”(YDZJ202101ZYTS113);山东省自然科学基金重点项目“蒿柳-丛枝菌根真菌修复多环芳烃污染土壤的协同强化机制研究”(ZR2020KC020)资助。

摘　　要：蒿柳(Salix viminalis)具有较强的镉(Cd)富集能力,但对高浓度Cd耐性低。研究褪黑素(MT)对高浓度Cd条件下蒿柳光合速率的调控作用,有助于揭示MT对木本植物Cd胁迫的缓解效应,为重金属污染植物修复提供栽培保障措施。以无性系蒿柳扦插苗为试验材料,设置空白(BT)、Cd胁迫(CT)、Cd胁迫后叶施MT(MCT)3个处理,明确MT对Cd胁迫下蒿柳气体交换参数、动态光下叶绿素荧光参数、1,5-二磷酸核酮糖羧化酶/加氧酶(Rubisco)含量等的调控模式。结果表明:在处理后第7天,Cd胁迫下蒿柳叶绿素a(Chla)和Rubisco含量分别降低了20%和21%;在处理后第14天,Cd胁迫下蒿柳叶绿素b(Chlb)、气孔导度(G_(s))、胞间二氧化碳浓度(C_(i))和净光合速率(P_(n))分别降低了32%、35%、23%和21%,叶施50μmol·L^(-1)MT后Chla、Chlb、G_(s)、C_(i)和Rubisco含量分别提高了30%、28%、47%、35%和25%;在处理后第21天,Cd胁迫下蒿柳P_(n)和光系统Ⅱ(PSⅡ)最大光化学效率(F_(v)/F_(m))分别降低了36%和16%,叶施MT后P_(n)和F_(v)/F_(m)分别提高了39%和13%;蒿柳受Cd胁迫后光抑制加剧,叶施MT减轻了光抑制。在Cd胁迫下,MT通过提高蒿柳气孔导度促进了蒿柳的光合气体交换,通过维持叶绿素含量促进了其光能吸收,通过提高光能转化效率及光合电子传递速率提升了其光合能力,通过提高Rubisco含量促进了其CO_(2)同化;MT通过提高光合作用强度促进了Cd胁迫下蒿柳的生长。Salix viminalis has an outstanding capacity to accumulate cadmium(Cd),but with poor tolerance to high concentrations of Cd.Investigating the regulation function of melatonin(MT)on photosynthetic rate of S.vimi-nalis exposed to high concentrations of Cd would help reveal the alleviation effect of MT on woody plants exposed to Cd and provide supporting measures for phytoremediation of heavy metals.Cutting seedlings of clonal S.viminalis were used as experimental material.Three treatments were set as blank(BT),Cd stress(CT),and foliar spraying MT followed by Cd stress(MCT).We examined the regulatory modes of MT on photosynthetic gas exchange param-eters,chlorophyll fluorescence parameters under dynamic light,and the content of ribulose-1,5-bisphosphate car-boxylase/oxygenase(Rubisco)in S.viminalis under Cd stress.The chlorophyll a(Chla)and Rubisco contents of S.viminalis exposed to Cd were decreased by 20%and 21%on the 7th day after treatment,respectively.The chlo-rophyll b(Chlb),stomatal conductance(G_(s)),intercellular CO_(2) concentration(C_(i)),net photosynthetic rate(P_(n))of S.viminalis exposed to Cd were decreased by 32%,35%,23%,21%on the 14th day after treatment.Under the treatment of spraying 50μmol·L^(-1) MT,Chl a,Chlb G_(s),C_(i),Rubisco content were increased by 30%,28%,47%,35%,25%respectively.P_(n) and photosystemⅡ(PSⅡ)maximum photochemical efficiency(F_(v)/F_(m))of S.viminalis exposed to Cd stress were decreased by 36%and 16%on the 21st day after treatment.After MT spra-ying,P_(n) and F_(v)/F_(m) were increased by 39%and 13%,respectively.Photoinhibition of S.viminalis exposed to Cd was aggravated,while spraying MT alleviated its photoinhibition.Under Cd stress,MT promoted photosynthetic gas exchange of S.viminalis by increasing stomatal conductance,promoted light harvesting by maintaining chlorophyll concentration,improved photosynthetic capacity by enhancing light energy conversion efficiency and photosynthetic electron transfer rate,and promoted CO_(2) assimilation by increasing Rubisco content

关 键 词：褪黑素 镉(CD) 蒿柳 光合速率 

分 类 号：X503.23[环境科学与工程—环境工程] Q945.78[生物学—植物学]