海岸带环境过程实验室知识库

(1) 鲁东大学生命科学学院

The effects of root abscisic acid(ABA)signal on Na~+ transport and photosystem Ⅱ(PSⅡ)in Jerusalem artichoke(Helianthus tuberosus)under salt stress(150 mmol·L~(-1)NaCl)were examined by applying ABA synthesis inhibitor sodium tungstate to roots. Sodium tungstate inhibited ABA synthesis in roots,reduced root Na~+ efflux,and increased the efficiency of Na~+ transport from roots to leaves under salt stress. Salt stress increased leaf Na~+ content and did not affect leaf membrane lipid peroxidation,PSⅡ reaction center protein and PSⅡ maximum photochemical efficiency(Fv /Fm). The inhibition on root ABA synthesis significantly increased leaf Na~+ accumulation, aggravated leaf membrane lipid peroxidation,impaired PS Ⅱ reaction center protein, decreased Fv /Fm,and induced PSⅡ photoinhibition. In conclusion,root ABA signal was beneficial to reducing leaf Na~+ accumulation and preventing PSⅡ oxidative damage by inducing root Na~+ efflux and inhibiting Na~+ transport to the aerial part in H. tuberosus under salt stress.

通过根系施加脱落酸(ABA)合成抑制剂钨酸钠,研究盐胁迫(150 mmol·L~(-1)NaCl)下菊芋根系ABA信号对根系Na~+转运、叶片Na~+积累和光系统Ⅱ(PSⅡ)的影响。结果表明:钨酸钠抑制盐胁迫下根系ABA合成,降低根系Na~+外排,提高根系Na~+向叶片的转运系数。盐胁迫增加叶片Na~+含量,没有影响叶片膜脂过氧化、PSⅡ反应中心蛋白合成和PSⅡ最大光化学效率(Fv /Fm)。根系ABA合成受抑制,显著增加盐胁迫下叶片Na~+积累,加剧叶片膜脂过氧化,损伤PSⅡ反应中心蛋白,显著降低Fv /Fm,诱发PSⅡ光抑制。总之,盐胁迫下菊芋根系ABA信号诱导根系Na~+外排,抑制Na~+向地上部转运,有利于减少叶片Na~+积累,防御PSⅡ氧化损伤。