植物色素在24-表油菜素内酯调节油菜耐盐性中的作用(英文)

Role of Plant Pigments in the 24-epibrassinolide Ameliorating Salt Stress in Canola

为了探索24-表油菜素内酯(24-EBL)对盐胁迫下油菜生长的调节效应和植物色素在油菜耐盐性中的作用,采用盆栽实验,在盐胁迫下外源喷施1 000、10、0.1、0.001nmol.L-1 24-EBL处理油菜幼苗,测定植株的生物量、电解质渗漏率(ELP)、净光合速率(Pn)、光合色素、酚类、类黄酮、花青素含量以及抗氧化能力(T-AOC)。结果显示:(1)24-EBL可显著缓解盐胁迫对油菜幼苗的氧化伤害,提高盐渍下油菜幼苗Pn和光合色素含量,并以0.1nmol.L-1 24-EBL(EBL3)对生长的调控效应最佳。(2)盐胁迫下,植株不同部位叶片的β-胡萝卜素(β-Car)和叶黄素(Lut)含量均显著下降,EBL3处理可显著提高其上部叶的β-Car含量,以及上部和中部叶的Lut含量;EBL3处理可显著提高盐胁迫下油菜所有叶片和叶柄的酚类含量,以及叶柄中类黄酮含量;EBL3处理可显著提高盐胁迫下油菜幼苗所有器官的花青素含量。(3)EBL3仅能够诱导上部叶和中部叶类胡萝卜素(Car)提取液的抗氧化能力(T-AOC)提高,但可诱导植株所有器官的酚类提取液的T-AOC提高。(4)不同部位的叶片Car、β-Car和Lut含量均与其Car提取液的T-AOC呈极显著正相关;而上部叶的总酚和花青素含量、中部叶和叶柄的花青素含量及茎秆中总酚、类黄酮和花青素含量与各自的酚类提取液的T-AOC呈极显著正相关。研究表明,外源喷施适宜浓度的24-EBL能够显著促进盐渍条件下油菜幼苗的光合能力,提高其抗氧化能力,从而增强其对盐渍胁迫的适应性,而光合色素和花青素水平被24-EBL诱导上升在油菜幼苗抗氧化过程中起着重要的作用。

This study evaluated effects of foliar spraying 24-epibrassinoide（24-EBL） on the growth of salt-stressed canola and plant pigment role played in canola salt tolerance.The seedlings were grown in the presence of 150 mmol·L-1 NaCl and sprayed with different concentration of 24-EBL（1 000,10,0.1,0.001 nmol·L-1） for 15 days.The plant biomass,electrolytic leakage percentage（ELP）,net photosynthetic rate（Pn）,contents of photosynthetic pigments,phenolics,flavonoids and anthocyanins,and total antioxidant capacity（T-AOC） of these plant pigments were determined.The results showed that：（1）24-EBL could ameliorate these adverse effects induced by salt on biomass,Pn,contents of chlorophyll（Chl） and carotenoid（Car）,MDA level and ELP.0.1 nmol·L-1 24-EBL（EBL3） was chosen as the optimal concentration for growth promotion and used in a subsequent experiment.（2）The levels of β-carotene（β-Car） and lutein（Lut） in different parts of leaves were sharply decreased under salinity,but β-Car content in upper leaves,Lut content in upper and middle leaves were reversed with varying degrees by EBL3.The treatment of EBL3 could promote the contents of phenolics in all leaves and petioles,and the contents of flavonoids in petioles of seedlings under salt stress.However,the anthocyanin contents of all plant organs were increased significantly induced by EBL3.（3）The treatment of EBL3 induced the T-AOC of carotenoid（Car） extracts in the upper and middle leaves.However,it induced the T-AOC of phenolics extracts in all plant organs of canola seedlings under salt stress.（4）Correlation analysis indicated that the T-AOC of carotenoids＇ extracts was all highly positively related to their contents of Car,β-Car and Lut.While,T-AOC of phenolics＇ extracts showed a positive correlation with contents of phenolics and anthocyanins in upper leaves,a very positive correlation with contents of phenolics and flavonoids in stems,and anthocyanins＇ contents of mid-leaves,petioles and stems.Sum up,foliar spraying 24-EBL could promote adaptation of the canola seedling to salt stress,which was due mainly to its increase of photosynthetic and antioxidant capacities induced by 24-EBL.Also,the increase of photosynthetic pigment and anthocyanin levels induced by 24-EBL played an important role in anti-oxidation of canola seedlings.