过表达OsbHLH120基因提高水稻苗期抗旱性

Overexpression of OsbHLH120 Enhance Drought Tolerance in Rice Seedling

干旱是限制水稻(Oryza sativa L.)产量和品质的主要因素之一,通过转基因方法是获得抗旱性水稻材料的重要途径。已有研究报道,水稻中多个Basic helix-loop-helix(bHLH)转录因子与抗旱性提高有关。为了研究OsbHLH120基因在水稻生长发育中的功能,通过构建过量表达载体、启动子驱动的GUS融合载体,转化水稻,获得了多个转基因株系。通过GUS染色结合实时荧光定量PCR结果研究该基因的表达特性,通过PEG干旱处理研究过表达植株对干旱的耐受性。结果发现,该基因在检测的幼苗、叶片和茎杆等组织中都有表达;PEG处理影响该基因的表达量;对过表达植株的PEG处理结果显示,过表达植株对干旱的耐受性增加;ABA合成相关基因在处理后的植株中的表达量提高,并且过表达植株中的表达量提高的更多。以上结果说明,OsbHLH120在水稻的抗旱反应中具有重要作用,是一个具有潜在应用价值的基因。

Drought is one of the main factors that affect rice(Oryza sativa L.) productivity and quality. We can obtain drought-improved rice materials through transgenic method. It was reported that some of HLH transcription factors were related with drought increase in rice. To investigate the function of OsbHLH120 in rice growth and development, we constructed the vector contain β-glucuronidase(GUS) reporter gene driven with the promoter of OsbHLH120 and the overexpression vector driven with the ubiquitin promoter. The expression pattern was analyzed with the GUS staining and real-time fluorescence PCR. Some transgenic lines were obtained for both of the constructions. Therefore we studied the drought tolerance of overexpression plants. The results showed the gene primary expressed in seedlings, leaves and stems. Its expression level was increased after treating with polyethylene glycol(PEG). The overexpression plants enhanced drought tolerance than wild type when they were treated with PEG for 2 days. And the relative transcription level of ABA biosynthesis genes were increased in PEG treated seedlings. Moreover their transcription level increased greater in overexpression plants than in wild type plants. These results indicated the OsbHLH120 plays an important role in rice drought treatment, and it may have important potential application value in rice breeding.