水稻NAL11基因对苗期非生物逆境的响应分析

Response Analysis of Rice Gene NAL11 to Abiotic Stresses at the Stage of Seedling

为了探究NAL11基因在水稻苗期对非生物逆境的响应机制及功能,对含NAL11基因的粳稻品种02428及其近等基因系NIL-8进行高温、低温、盐胁迫和模拟干旱胁迫处理,以正常处理的植株作为对照,观察植株表型、测定各处理下叶片的多种生理指标,并比较NAL11基因在不同逆境处理下的表达量情况。研究结果发现,高温、低温、盐胁迫处理导致02428与NIL-8均表现出一定程度的萎蔫、干枯症状,但两者差异并不明显;15%PEG-6000模拟干旱处理均导致二者叶片萎蔫、叶尖枯黄卷曲,但NIL-8植株的症状相对较轻,且与02428相比NIL-8的相对电导率降低、SPAD值增高;其次,与02428相比,NIL-8的SOD含量差异不显著;然而在低温和干旱胁迫下,NIL-8的CAT含量显著高于02428。表明NIL-8比02428具有更好的抗旱能力。实时定量PCR结果表明,高温、低温、盐害及模拟干旱胁迫下,NAL11表达量均迅速升高,随着处理时间的延长,其表达量表现出不同的动态变化。NAL11基因的表达受高温、低温、盐及模拟干旱胁迫的诱导,但表达模式各异;推测NAL11基因对水稻幼苗的抗旱能力起到一定的调节作用。

In order to explore the response mechanism and the function of gene NAL11 to abiotic stress at the stage of rice seedling,we treated the Oryza sativa L.subsp.Japonica cv.02428,contained gene NAL11,and its near-isogenic line NIL-8 with high temperature,low temperature,salt stress and simulated drought stress,respectively,with the plants under normal conditions as control.In the case,the phenotypes and some physiological indices of the plants under each treatment were observed and assayed.Then,we compared the expressions of gene NAL11 under different stress treatments,and some phenomena were found to be interesting.Firstly,under the independent treatments of high temperature,low temperature and salt stress,02428 and NIL-8 showed a similar degree of wilting and drying symptoms,which were very mild.However,when treated with 15%PEG-6000,leaves of 02428 and NIL-8 turned wilted,and the leaf tips became yellow and curly,but the symptoms of NIL-8 were relatively slighter than 02428.Besides,NIL-8 showed lower relative conductivity and higher SPAD value than 02428.Meanwhile,compared with 02428,there was no significant change in SOD activities of NIL-8,but the CAT activities of NIL-8 was significantly higher than that of 02428 under low temperature and drought stress.The above results indicated that NIL-8 possessed a better drought resistance than 02428.From the Real-time quantitative PCR,we could see that the expression of gene NAL11 increased rapidly after treated with high temperature,low temperature,salt stress and simulated drought stress individually,and the expression changed dynamically along with the extension of treatment time.Thus,it is concluded that the expression of gene NAL11 would be induced by high temperature,low temperature,salt stress and simulated drought stress,but the expression patterns were different.So it is reasonable for us to suppose that gene NAL11 plays a certain role in the drought resistance of rice seedlings.