小麦乙烯响应转录因子基因wfzp突变体颖果发育的研究

Caryopsis Development of wfzp Mutants of Ethylene Response Transcription Factor Gene in Wheat

小麦WFZP基因编码的乙烯响应因子是植物中特有的转录因子,参与果实成熟、花叶器官衰老、脱落和种子发育等过程。为探明wfzp基因突变对小麦颖果发育的影响,以甲基磺酸乙酯诱变的两个wfzp基因突变体(wfzp1和wfzp2)和野生型小麦品种济麦22为材料,运用树脂超薄切片和显微观察技术观察小麦WFZP基因突变体颖果的形态结构发育特征。结果显示,wfzp突变体颖果发育有如下特征:(1)在颖果发育早期,两个突变体的外果皮发育进程较快,中果皮降解时间提前;wfzp1内果皮管细胞消失较快,与wfzp1突变体相比,wfzp2突变体的管细胞发育缓慢;(2)两个突变体胚乳细胞的分化和发育明显较快,细胞中淀粉和蛋白体的积累量明显增多,细胞的充实度高,尤其在wfzp2突变体中表现较为明显;(3)两个突变体胚乳传递细胞与糊粉层传递细胞的生长分化进程加快。研究结果为进一步探究乙烯响应转录因子调控小麦颖果发育提供了形态学参考。

The WHEAT FRIZZY PANICLE(wfzp)gene encoding a member of the APETALA2/Ethylene response factor transcription factor family,is a unique transcription factor in plants.It is involved in fruit ripening,senescence of flower and leaf organs,abscission and seed development.In order to clarity the effect of wheat WFZP gene mutation on caryopsis development of wheat,two wheat mutants(wfzp1 and wfzp2)of WFZP gene generated by ethyl methanesulfonate and the wild type wheat Jimai 22 were used as experimental materials in this study.The morphology and structure characteristics of wheat caryopsis of wfzp mutants were observed using resin slicing and microscopic observation technology.Observation of morphological structure at different parts of caryopsis showed that:(1)At the early stage of caryopsis development,the epicarp development process of the two wheat wfzp mutants were faster,and the degradation time of mesocarp was earlier,in comparison to Jimai 22.The tube cells of the pericarp disappeared rapidly in wfzp1.Compared to wfzp1,the endocarp tube cell in wfzp2 was slowly developed;(2)The differentiation and development of endosperm cells were obviously faster in wfzp mutants than that in Jimai 22,and the endosperm plumpness of endosperm cells was higher than that in Jimai 22.(3)Compared with Jimai 22,more amyloplasts and protein bodies were accumulated in endosperm cell,especially in wfzp2 mutant;the growth and differentiation of endosperm transfer cells and aleurone transfer cells were accelerated in wfzp mutants.These results provide morphological reference and help further elucidate the functions of ethylene responsive transcription factors during caryopsis development in wheat.