独脚金内酯缓解油菜渍水胁迫的生理机制

摘要

In order to alleviate waterlogging stress and promote rapeseed (Brassica nuapus L.) growth,effects of strigolactones on root-shoot biomass and physiological traits were investigated.In pot experiments,Zhongshuang 11 seedlings at 5-leaf stage were waterlogged for 7d.Then both seedlings from waterlogged group and control group were root-irrigated by strigolactones (SL) in 4 concentrations (0,0.1,1 and 5 μmol/L).The root and shoot growth,photosynthesis and antioxidant enzyme were investigated at 3d and 7d after strigolactones treatments respectively.Results showed that both the root and shoot dry weight increased significantly after 1 μmol/L SL treatment for 3d and 7d in waterlogged group.The net photosynthetic rate (Pn),stomatal conductance (Gs) and transpiration rate (Tr) were significantly increased,while the intercellular CO2 concentration (Ci) decreased.The relative electron transfer efficiency (rETR),PS Ⅱ maximum photochemical efficiency (Fv/Fm),PS lⅡ potential activity (Fv/Fo),PS Ⅱ effective quantum yield (Fv'/Fm') and PS Ⅱ actual energy conversion efficiency (ΦPSⅡ) increased,but nonphotochemical quenching efficiency (qN) decreased.Meanwhile,leaf chlorophyll,POD and CAT activities increased,whereas SOD activity decreased.The results showed that 1 μmol/L SL effectively alleviated the waterlogging stress.It promoted seedlings growth by increasing biomass,photosynthetic efficiency,photosynthetic pigment content,and reducing non-photochemical quenching and SOD activity.%为了缓解渍水危害,维持并促进油菜生长,探究独脚金内酯对渍水处理后油菜生长的影响,以中双11号为材料进行盆栽试验,五叶期渍水处理7d后,分别用0、0.1、1和5μmol/L独脚金内酯(SL)对渍水胁迫组(W)和正常水分组(C)进行灌根处理.在灌根后第3d和7d测定油菜干鲜重、光合气体交换参数、荧光参数、叶绿素含量以及抗氧化酶活性的变化.结果表明,1 μmol/独脚金内酯显著提高了渍水处理7d后油菜的地上部和地下部的生物量;显著提高了净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),降低了胞间CO2浓度(Ci);增加了相对电子传递效率(rETR)、PSⅡ最大光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、PSⅡ有效光化学量子产量(Fv'/Fm')和PSⅡ实际光能转换效率(ΦPSⅡ);降低了非光化学淬灭系数(qN);提高了叶片的叶绿素含量、POD以及CAT酶活性,而降低了SOD酶活性.可见采用1μmol/L独脚金内酯灌根能够有效缓解渍水胁迫,通过提高生物量的积累、光合作用效率、光合色素含量、部分叶绿体荧光参数,降低非光化学猝灭和SOD酶活性等以促进受渍油菜幼苗恢复生长.