摘要
[目的]旨在研究不同NaCl胁迫条件下‘心文41号’(Juglans cordiformis‘Xinwen No.41’)核桃幼苗的生理特性及离子转运、丝裂原活化蛋白激酶(MAPK)级联信号基因表达的响应差异。[方法]采取盆栽控盐的方法,选择长势一致的‘心文41号’核桃幼苗作为试验对象,设置100、150、200 mmol·L^(-1)3个NaCl浓度进行处理,同时以清水作为对照组(CK)。经过20 d的胁迫处理,对幼苗的表型、光合等指标进行了测定,通过非损伤微测技术(NMT)评估了根系Na^(+)、K^(+)、H^(+)通量。提取叶片和根部的RNA测定MAPK级联信号传导和离子转运相关基因的表达。通过冗余分析(RDA)探究了生理指标与基因表达之间的相关性,旨在揭示心形核桃幼苗对盐胁迫调节机制的反应特征。[结果]随着NaCl浓度增加,心形核桃幼苗的根系体积和总生物量显著减少,叶片出现枯黄和萎蔫现象。光合生理参数(净光合速率、蒸腾速率和气孔导度)呈下降趋势,胞间CO_(2)浓度逐渐增加。叶片和根系中超氧化物歧化酶(SOD)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)活性,脯氨酸(Pro),丙二醛(MDA)和过氧化氢(Hydrogen peroxide,H_(2)O_(2))含量均出现不同程度的增加,根系中Na^(+)含量显著积累,随盐浓度增加其外排趋势明显,叶片中K^(+)外排和H^(+)内流以维持胞内渗透势的稳态。耐盐相关基因质膜Na^(+)/H^(+)逆向转运体(Salt Overly Sensitive,SOS1)在叶片表达量高于根系,液泡膜Na^(+)/H^(+)逆向转运体1(NHX1)呈先上调后下调的趋势,且液泡H^(+)-ATPase c亚基(VHA-C1)在根系中显著上调。在100 mmol·L^(-1)NaCl浓度胁迫下,WRKY65(WRKY transcription factor 65)、MKK9(Mitogen-activated protein kinase kinase 9)和MPK3(Mitogen-activated protein kinase 3)基因的表达呈上升趋势,且叶片中的表达量显著高于根系。[结论]NaCl胁迫条件下,心形核桃根系受胁迫影响大于叶片,JrSOS1、JrNHX1、JrNHX2与抗盐能力密切相关,
[Objective]This study investigated the physiological characteristics and differential responses of ion transport and mitogen activated protein kinase(MAPK)cascade signaling genes in Juglans cordiformes'Xinwen No.41'walnut seedlings under different NaCl stress conditions.[Methods]Pot planting was employed to explore the response of‘Xinwen No.41’walnut seedlings with same growth to salt stress treatments with three salt concentrations-100,150,and 200 mmol·L^(-1) to.,and the water treatment was served as control group(CK).Following 20 days of treatment,the phenotypic and photosynthetic parameters of the seedlings were measured.Non-invasive micro-test technology(NMT)was utilized to assess root Na^(+),K^(+),and H^(+)fluxes.RNA was extracted from both leaves and roots for gene expression analysis related to MAPK cascade signaling transduction and ion transport.Redundancy analysis(RDA)was employed to explore the correlations between physiological indicators and gene expression,aiming to elucidate the salt stress response and regulatory mechanisms in walnut seedlings.[Results]Increasing salt concentrations resulted in significant reductions in root volume and total biomass of the seedlings,accompanied by leaf withering and wilting.Photosynthetic parameters such as net photosynthetic rate,transpiration rate,and stomatal conductance exhibited declining trends,while the intercellular CO_(2) concentrations increased.Activities of superoxide dismutase(SOD),peroxidase(POD),ascorbate peroxidase(APX)activities,Pro,MDA and H_(2)O_(2) contents in leaves and roots increased significantly.Na^(+)content in roots significantly accumulated and showed a clear trend of efflux with increasing salt concentration,while K^(+)efflux and H^(+)influx in leaves maintained intracellular osmotic potential homeostasis.Salt-tolerant-related genes,such as plasma membrane Na^(+)/H^(+)antiporter(SOS1)exhibited higher expression levels in leaves,while the Sodium/hydrogen antiporter 1(NHX1)was up-regulated and then down-regulated.Moreover,Vacuolar H
作者
郑旭
李敖
姬新颖
聂瑞宁
吴承勖
唐佳莉
张俊佩
ZHENG Xu;LI Ao;JI Xin-ying;NIE Rui-ning;WU Cheng-xu;TANG Jia-li;ZHANG Jun-pei(State Key Laboratory of Tree Genetics and Breeding·Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration·Research Institute of Forestry Chinese Academy of Forestry,Beijing 100091,China)
出处
《林业科学研究》
CSCD
北大核心
2024年第5期105-115,共11页
Forest Research
基金
国家重点研发计划课题(2022YFD2200402)国家级。
