PagHK3a基因敲除对银腺杨抗旱性的影响  

Effects of PagHK3a Gene Knockout on Drought Resistance of Populus alba×P.glandulosa

作　　者：武舒 王洲 张明艳 钟姗辰 王黎 苏晓华[1] 张冰玉[1] WU Shu;WANG Zhou;ZHANG Ming-yan;ZHONG Shan-chen;WANG Li;SU Xiao-hua;ZHANG Bing-yu(Research Institute of Forestry Chinese Academy of Forestry,State Key Laboratory of Tree Genetics and Breeding,Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration,Beijing 100091,China)

机构地区：[1]中国林业科学研究院林业研究所、林木遗传育种全国重点实验室、国家林业和草原局林木培育重点实验室,北京100091

出　　处：《林业科学研究》2023年第5期1-11,共11页Forest Research

基　　金：国家“十四五”重点研发课题(2021YFD2200103)。

摘　　要：[目的]:对银腺杨(Populus alba×P.glandulosa‘84k’)组氨酸激酶PagHK3a基因敲除株系的抗旱性进行评价,同时探究PagHK3a基因在杨树响应干旱胁迫过程中的分子调节机制。[方法]:利用5%PEG模拟干旱胁迫处理继代25 d的野生型银腺杨(WT)及其PagHK3a基因敲除株系(C1和C2)组培苗,处理3 h后采用实时定量PCR(Quantitative real-time PCR)方法测定各株系叶片PagHK3a基因、PagHK3a下游基因、干旱胁迫响应基因及抗氧化基因的表达水平;利用称重控水法对各株系盆栽苗进行3个梯度的温室干旱胁迫处理,包括正常浇水(土壤相对含水量:70%~75%)、中度干旱(40%~45%)以及重度干旱(25%~30%),干旱胁迫4周后测定WT及C1、C2株系的瞬时光合参数、过氧化氢(H_(2)O_(2))及丙二醛(MDA)含量、过氧化物酶(POD)及超氧化物歧化酶(SOD)酶活性、株高和地径等生理生化及生长指标。[结果]:在温室中度干旱条件下,C1和C2株系株高生长量均显著高于WT,而在重度干旱条件下,这两个株系的株高生长量与WT相比均无显著差异。分析光合参数发现,在中度干旱条件下,基因敲除株系C1和C2气孔导度及胞间CO_(2)浓度均显著高于WT,但在重度干旱胁迫条件下只有C2株系胞间CO_(2)浓度显著高于WT;在中度干旱胁迫条件下C1株系瞬时净光合速率显著高于WT,在重度干旱胁迫条件下,C2株系瞬时净光合速率显著高于WT。同时生化指标测定结果显示,在中度干旱条件下基因敲除株系C1和C2中MDA及H_(2)O_(2)含量显著低于WT,而在重度干旱胁迫时,仅C2株系显著低于WT;对比分析各株系抗氧化酶活性发现,正常供水条件下,C1株系叶片POD酶活性以及C2株系SOD酶活性显著高于WT,在中度干旱胁迫条件下,C1株系这两种保护酶活性均显著高于WT,而C2株系仅在重度干旱胁迫下显著高于WT。另外,在PEG模拟干旱胁迫处理下,基因敲除株系C1和C2叶片组氨酸激酶基因PagHK3a及其下游响应调节蛋[Objective]:This study aimed to evaluate the drought resistance of two histidine kinase PagHK3a gene knockout lines of poplar'84k'(Populus alba×P.glandulosa'84k'),and explore the molecular regulatory mechanism of PagHK3a gene in poplar response to drought stress.[Method]:Plantlets of wild-type(WT)and gene knockout strains(C1 and C2)sub-cultured for 25 days were treated with 5%PEG and the mature leaves of the plantlets were gathered 3 hours later.Quantitative real-time PCR(qPCR)was used to detect the expression levels of PagHK3a gene,PagHK3a downstream related genes,drought stress response genes and antioxidant related genes in leaves of the three lines.Meanwhile,the drought stress treatment was carried out using the potted plants of each line by weighing method with three levels:normal watering greenhouse(soil relative water content:70%-75%),moderate drought(40%-45%)and severe drought(25%-30%).After four weeks of drought stress treatment,transient photosynthetic parameters,contents of hydrogen peroxide(H_(2)O_(2))and malondialdehyde(MDA),activities of peroxidase(POD)and superoxide dismutase(SOD),plant height and ground diameter of WT and C1,C2 were measured.[Result]:Under moderate drought conditions,the height growth of both C1 and C2 lines was significantly higher than that of WT,but under severe drought conditions,the height growth of both lines was not significantly different from that of WT.Analysis of photosynthetic parameters revealed that the stomatal conductance and intercellular carbon dioxide concentration of C1 and C2 were significantly higher than those of WT under moderate drought condition,but only C2 was significantly higher than that of WT under severe drought stress condition.Under moderate drought stress,the instantaneous net photosynthetic rate of C1 was significantly higher than that of WT,and under severe drought stress,the instantaneous net photosynthetic rate of C2 was significantly higher than that of WT.At the same time,the results of biochemical indexes showed that MDA and H_(2)O_(2)con

关 键 词：银腺杨 组氨酸激酶基因PagHK3a 基因敲除 抗旱性 

分 类 号：S722[农业科学—林木遗传育种]