高温胁迫下喷施外源一氧化氮对恢复生长期菜豆幼苗相关生理特性的影响

Effects of Spraying Exogenous Nitric Oxide under High Temperature Stress on Physiological Characteristics of Phaseolus vulgaris L.in Recovery Growth Period

【目的】缓解高温胁迫对菜豆幼苗的伤害。【方法】以闽西地方菜豆品种黄种豆幼苗为试材,在高温胁迫下喷施不同浓度的外源一氧化氮供体硝普钠(sodium nitroprusside,SNP),观察测定幼苗生长的变化,并测定其相关生理指标的变化,探讨SNP对恢复生长期幼苗生理特性的影响。【结果】高温胁迫明显抑制菜豆幼苗生长,导致叶片灼伤、萎蔫卷曲,其株高、茎粗、鲜质量和干质量显著低于常温对照,适宜浓度的SNP(0.5~1.0 mmol/L)处理可以有效改善胁迫条件下幼苗表型及株高和茎粗,其中以0.7 mmol/L SNP处理效果最佳。恢复生长试验结果表明:与常温对照相比,结束高温胁迫0 h时幼苗叶片叶绿素、可溶性糖、可溶性蛋白、脯氨酸和内源NO含量以及SOD和CAT活性均显著降低,MDA含量和POD活性显著升高;高温胁迫下喷施SNP可提高恢复期幼苗叶片的叶绿素、渗透调节物质和内源NO含量,促进抗氧化酶活性,降低MDA含量,各指标均以0.7 mmol/L SNP处理最优,且在恢复生长48~72 h时最接近常温生长幼苗。【结论】高温胁迫下喷施一定浓度的SNP可有效保护菜豆幼苗生长并促进生长恢复。

[Purpose]To mitigate the damage of high temperature stress to Phaseolus vulgaris L.[Methods]Different concentrations of exogenous nitric oxide donor sodium nitroprusside(SNP)were sprayed to the test material‘Yellow Seed Bean’seedlings,a local kidney bean variety in west Fujian,under high temperature stress.The growth changes of the seedlings were observed and determined,and the changes of the relevant physiological indicators were determined to study the effects of SNP on the physiological characteristics of the seedlings in the recovery growth period[Results]High temperature stress obviously inhibited the growth of P.vulgaris,resulting in leaf burns,wilting and curling,with the plant height,stem diameter,fresh weight and dry weight significantly lower than normal temperature control.Treatment with appropriate concentrations of SNP(0.5-1.0 mmol/L)could effectively improve the phenotype and the growth of plant height and stem diameter of P.vulgaris under stress conditions,and the effects of treatment with 0.7 mmol/L SNP were the best.The growth recovery test results showed that:compared with those under normal temperature control,the contents of chlorophyll,soluble sugar,soluble protein,proline and endogenous NO,and the activities of SOD and CAT in the leaves of P.vulgaris were significantly reduced,and the MDA content and POD activity were significantly increased after high temperature stress;the contents of chlorophyll,osmoregulation substances and endogenous NO in the leaves of P.vulgaris in the recovery stage were significantly increased,the antioxidant enzyme activities were promoted and the MDA contents were reduced by spraying exogenous nitric oxide under high temperature stress.The indicators were the best under the treatment with 0.7 mmol/L SNP,and were close to those of the P.vulgaris growing at normal temperature after recovery 48-72 hours.[Conclusion]Spraying a certain concentration of SNP under high temperature stress can effectively protect the growth of P.vulgaris and promote its growth recovery.