多种外源激素处理对水稻叶片衰老的影响

摘要

为明确多种外源激素的不同浓度对水稻叶片衰老的影响情况,采用野生型水稻日本晴(NIP)和早衰突变体(esd1)为试验对象,通过外源喷施多种外源激素,包括生长素(2,4-D)、脱落酸(ABA)、赤霉素(GA3)、水杨酸(SA)、细胞分裂素(KT-30)、油菜素内酯(GR24),检测了NIP和esd1叶片中与衰老相关的生理指标(包括叶绿素含量,丙二醛(MDA)含量,超氧化物歧化酶(SOD)活性).研究结果表明:在灌浆期,喷施2,4-D会增加NIP和esd1叶片中的w(叶绿素a:叶绿素b),喷施GA3和低浓度的KT-30会降低NIP和esd1叶片中MDA的含量,说明喷施外源激素2,4-D、GA3和低浓度的KT-30具有延缓衰老的作用,且都对esd1的延缓作用更为明显;而喷施ABA会降低NIP和esd1叶片中的w(叶绿素a:叶绿素b),说明具有加速衰老的作用,对NIP的作用较明显;幼苗期喷施SA,发现NIP和esd1的叶片中SOD酶活性下降,但变化程度不明显;另外,喷施GR24对叶片衰老没有起到延缓的作用,但发现esd1对这2个激素敏感反应更大.本研究发现喷施外源植物激素对水稻延缓衰老具有可行性,这为探究激素生理奠定一定的理论基础,同时对水稻生产起到一定的参考作用.%The effect of exogenous hormone on the rice leaf senescence at the physiological level was re -searched,which provided a theoretical basis for studying how plant hormones affected leaf senescence.The wild type Nipponbare(NIP)and its premature senescence mutant(esd1)were used as material,after sprayed a variety of exogenous hormones including auxin(2,4-D),abscisic acid(ABA),gibberellins(GA3),sali-cylic acid(SA),cytokinins(KT-30),brassinosteroids(GR24),then it was detected the physiological indi-ces related to senescence(including chlorophyll content, malondialdehyde(MDA)content, superoxide dis-mutase(SOD)activity, and so on).The experiments results showed that: during grain-filling rate stage,spraying 2,4-D increased the chlorophyll a/chlorophyll b content both of NIP and esd1,spraying GA3and low KT-30 concentration reduced the content of MDA in NIP and esd1 leaves,which indicated that spraying exoge-nous hormone delayed rice leaf senescence,and appeared more obvious in esd1;however,spraying ABA de-creased the chlorophyll a/chlorophyll b content both of NIP and esd1,which indicated that spraying ABA ac-celerated rice leaf senescence, and appeared more obvious in NIP.During the seedling stage spraying SA, found the SOD content were decreased both of NIP and esd1,but the degree of change was not obvious,in ad-dition,GR24 had not affect in delay leaf senescence,but esd1 showed more sensitive to SA and GR24.It was also found that spray exogenous hormone was feasible to delay leaf senescence,which laid a theoretical founda-tion for study hormone physiology,and would play a reference role in rice production.