东京四照花钙组分与渗透调节物质对盐胁迫的响应  

Responses of Calcium Composition and Osmotica under Salt Stress in Cornus hongkongensis Subsp.Tonkinensis(W.P.Fang)Q.Y.Xiang

作　　者：袁佳秋 孙大伟 杨玲 洑香香 YUAN Jiaqiu;SUN Dawei;YANG Ling;FU Xiangxiang(Jiangsu Food&Pharmaceutical Science College,Huai’an 223005,P.R.China;Co-Innovation Center for the Sustainable Forestry in Southern China/College of forestry,Nanjing forestry university,Nanjing 210037,P.R.China;Shanghai Wildlife and Protected Natural Areas Research Center,Shanghai 200336,P.R.China)

机构地区：[1]江苏食品药品职业技术学院,江苏淮安223005 [2]南方现代林业协同创新中心/南京林业大学林学院,江苏南京210037 [3]上海市野生动植物和自然保护地研究中心,上海200336

出　　处：《生态环境学报》2023年第4期687-696,共10页Ecology and Environmental Sciences

基　　金：江苏省林业科技创新与推广项目(LYKJ[2018]06);江苏省高校重点学科建设项目(PAPD);江苏省研究生科研实践与创新计划项目(KYCX21_0888)。

摘　　要：随着滨海地区土壤盐渍化程度不断扩大,选育耐盐性和观赏价值并存的木本植物进行引种栽培,将有利于盐渍土壤资源的利用和生态系统的改善。东京四照花(Cornushongkongensissubsp.tonkinensis)作为观赏型苗木,从幼苗的钙组分与渗透物质方面探讨其盐胁迫响应机制,为其在滨海地区推广种植提供理论依据。设置4种质量分数梯度的盐浓度:0(CK)、0.20%(T1)、0.30%(T2)和0.45%(T3),水培法培养幼苗。盐处理幼苗的盐害等级(ISD)随着盐分浓度的升高和胁迫时间的延长而增加。盐胁迫5d时,各处理组的幼苗ISD和成活率未有明显变化;盐胁迫30d时,T1、T2和T3处理组的ISD分别为47.80%、52.00%和71.20%,对应的成活率分别为82.60%、84.00%和56.00%。胁迫初期(5 d),T1、T2和T3保卫细胞中Ca^(2+)浓度较CK分别增加了13.98%、22.54%和17.33%。同时,T1、T2和T3的气孔孔径的宽长比(W/L)比CK分别减少了23.60%、25.98%和36.05%。其中,仅T3处理保卫细胞中Ca^(2+)浓度随胁迫时间延长而显著升高。胁迫至30 d,T3处理下的水溶性钙(H2O-Ca)、草酸钙(HCl-Ca)、果胶酸钙(NaCl-Ca)质量分数分别降低至4.99、7.12、4.04 mg·g^(-1)。同时,随着盐浓度的升高,草酸钙晶体在叶肉细胞中破碎化程度明显。与CK相比,T1、T2和T3草酸钙晶体在叶肉细胞中面积占比分别显著降低了43.10%、15.25%、69.90%。T3处理下的可溶性蛋白(SP)、可溶性糖(SS)和脯氨酸(Pro)含量较CK分别增加了20.04%、15.38%和19.74%。东京四照花短期(30 d)可承受0.45%的盐胁迫。幼苗通过提高Ca^(2+)浓度,促进可溶性蛋白的合成来提高其耐盐性。此外,草酸钙降解释放出的Ca^(2+)可能是缓解盐胁迫对东京四照花幼苗损伤的有效策略。The continuous expansion of soil salinization in coastal areas necessitates the selection and breeding of woody plants with both salt tolerance and ornamental value.This practice is vital for utilizing saline soil resources and enhancing the ecosystem.To elucidate the response mechanism to salt stress,we analyzed the effects of varying concentrations of salt stress on calcium components and osmotic substances in Cornus hongkongensis subsp.tonkinensis seedlings.The results can serve as a theoretical foundation for promoting and cultivating ornamental dogwood in coastal areas.The study involved the hydroponic cultivation of seedlings with four gradient concentrations of sea salt[0(CK),0.20%(T1),0.30%(T2),and 0.45%(T3)].The degree of salt damage index(ISD)in salinized seedlings increased with both the rising salt concentration and the extension of stress duration.After 5 days of salt stress,the ISD and survival rate in salinized seedlings showed no significance.Salinized seedlings exposed to T1,T2,and T3 exhibited ISD of 47.80%,52.00%,and 71.20%after 30 days of salt stress,and the corresponding survival rates were 82.60%,84.00%,and 56.00%.During short-term saline stress(5 d),the Ca^(2+)concentration in the guard cells of leaves exposed to T1,T2,and T3 increased,reaching 13.98%,22.54%,and 17.33%above CK,separately.Simultaneously,the width-to-length ratios of pore in T1,T2,and T3 were lower than that in CK by 23.60%,25.98%,and 36.05%,respectively.Thereof,the Ca^(2+)concentration in the guard cells of leaves exposed to T3 increased strikingly with the extension of stress duration.After 30 days of salt stress,the mass fractions of water-soluble calcium,oxalate calcium,and pectin-bound calcium in T3 significantly decreased to the values of 4.99,7.12,and 4.04 mg·g-1,respectively.Additionally,as the salt concentration increased,there was obvious fragmentation of calcium oxalate crystals in mesophyll cells.The area proportion of calcium oxalate crystals in mesophyll cells exposed to T1,T2,and T3 fell by 43.10%,15.25%,and 6

关 键 词：盐胁迫 钙组分 草酸钙 渗透物质 东京四照花 

分 类 号：Q945[生物学—植物学] X17[环境科学与工程—环境科学]