文献类型：期刊文献

中文题名：水通道蛋白PIP1基因过表达杨树的光合生理过程对干旱和复水的响应

英文题名：Responses of Photosynthetic Physiological Process of a Poplar with Overexpressed PIP1 Gene to Drought Stress and Rehydration

作者：刘文鑫[1] 陈志成[1] 代永欣[2] 万贤崇[1]

第一作者：刘文鑫

通信作者：Wan, Xianchong

机构：[1]中国林业科学研究院林业新技术研究所,北京100091;[2]山西农业大学林学院,太谷030800

年份：2020

卷号：56

期号：2

起止页码：69-78

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;EI(收录号：20201408371239);Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：中国林业科学研究院林业新技术研究所中央级公益性科研院所基本科研业务费专项资金项目(CAFYBB2018SZ019);国家自然科学基金项目(31270648)

语种：中文

中文关键词：杨树;叶肉导度;光合限制;水通道蛋白

外文关键词：poplar;mesophyll conductance;photosynthesis limitation;aquaporin

分类号：S718.43

摘要：【目的】通过比较转水通道蛋白基因PtPIP1;3(GenBank登录号:MN795092 ptopip1.3)的84K杨与野生型植株的光合作用对干旱及复水的响应,分析该过程的限制因素,以期深入了解水通道蛋白PIP1在干旱胁迫及复水过程中对CO2导度的调节作用及其对光合作用的影响。【方法】以杂交杨84K野生型及转PtPIP1;3基因植株为研究对象,进行重度干旱胁迫(土壤含水量达到田间持水量的35%)及复水处理,测定气体交换及叶绿素荧光各个指标,计算叶肉导度(gm)等参数,进而分析水通道蛋白在干旱条件及复水后对CO2导度和光合作用的调节作用。【结果】转PtPIP1;3基因84K杨在正常浇水下净光合速率(Pn)、气孔导度(gs)和蒸腾速率(Tr)显著高于84K野生型。干旱胁迫至第6天,野生型和转基因植株光合作用都开始下降,且转基因植株光合作用下降速度更快,至第7天降到野生型同样的水平。干旱处理的第7~10天,转基因植株和野生型植株的gs、gm和Pn均显著低于各自对照(正常浇水植株),光化学淬灭(qP)、光系统Ⅱ实际光化学效率(ФPSⅡ)、电子传递速率(Jflu)、最大羧化速率(Vcmax)和最大电子传递速率(Jmax)也显著降低,此时2种植株的光合作用都主要受到叶肉导度的限制。在复水的3天过程中,转基因植株的光合作用恢复速度更快,而且叶绿素荧光参数能够恢复到正常水平,期间光合作用主要受到叶肉导度的限制;而野生型植株的光合参数以及叶绿素荧光参数都未完全恢复,其光合作用除了受到叶肉导度的限制外,还受到光合作用中生物化学过程的限制。【结论】叶肉导度是转水通道蛋白基因及野生型84K杨干旱胁迫和复水过程中光合作用的主要限制因素。在干旱胁迫后水通道蛋白基因过表达的转基因杨树光合作用恢复迅速,包括光系统Ⅱ性能的恢复,这有助于杨树适应自然界中经常发生的阶段性干旱胁迫。
【Objective】The responses of photosynthetic process to drought stress and re-watering of the wild type and PtPIP1;3(GenBank accession No.MN795092 ptopip1.3)transgenic poplar variety‘84K’(Populus alba×P.glandulosa‘84K’)were compared to analyze the limitation factors to photosynthesis in order to further understand the function of aquaporin PIP1 in regulation of CO2 conductance and the influences on photosynthesis.【Method】The wild type and PtPIP1;3 transgenic poplar variety‘84K’were subjected to severe drought stress(The soil water content reaches 35%of the field water capacity)and re-watering.The gas exchanges and chlorophyll fluorescence parameters of the leaves were measured,with which the mesophyll conductance(gm)and other relevant parameters were calculated.Then the regulation of aquaporin in CO2 conductance and photosynthesis after drought stress and re-watering was analyzed.【Result】Net photosynthetic rate(Pn),stomatal conductance(gs)and transpiration rate(Tr)of transgenic poplars were significantly higher than those of wild type plants under normal watering regime.After six days of drought treatment,Pn of transgenic and wild type poplars started to decrease significantly,and the former decreased more rapidly than the latter and reached to the same level of the latter’s on day 7 and the remaining time of drought treatment.During the 7-10 days of drought treatment,gs,gmand Pn of transgenic and wild type poplars were significantly lower than their own control(normally watered plants).So did photochemical quenching(qP),actual photochemical efficiency of photosystemⅡ(ФPSII),electron transport rate(Jflu),Rubisco maximum carboxylation rate(Vcmax)and maximum electron transport rate(Jmax).Photosynthesis of transgenic and wild type poplars were mainly limited by mesophyll conductance.After three days of re-watering,photosynthesis of transgenic poplars recovered more quickly and chlorophyll fluorescence parameters restored to the normal level,whereas,chlorophyll fluorescence of wild type poplars did not fully recover.Mesophyll conductance was still the main limitation factor,while biochemical limitation was the second major limitation factor.【Conclusion】Mesophyll conductance was the main limitation factor of photosynthesis of PtPIP1;3 transgenic and wild type poplar‘84K’during drought stress and re-watering.The photosynthesis of PtPIP1;3 transgenic poplar recovered quickly with re-watering after drought stress including the recovery of photosynthesis system II,which might help plants survive in nature wherein the stress stimuli is often transient but periodical.