水稻糊粉层蛋白酶体参与种子萌发的研究  

Proteasomes Involved in Seed Germination in Rice Aleurone Layer

作　　者：陈文奕 陈惠萍[1] CHEN Wenyi;CHEN Huiping(College of Life Science,Hainan University,Haikou,Hainan 570228,China)

机构地区：[1]海南大学生命科学学院,海南海口570228

出　　处：《热带作物学报》2024年第4期752-760,共9页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31960453)。

摘　　要：种子萌发是植物进入营养生长阶段的关键性环节,在水稻(Oryza sativa L.)种子萌发过程中,糊粉层会合成并分泌一系列的酸性水解酶(如α-淀粉酶、蛋白酶)用于降解胚乳中的贮藏物质,为水稻幼苗生长提供营养。水稻种子贮藏蛋白的降解离不开蛋白酶体及蛋白酶的作用。为探究26S蛋白酶体、20S蛋白酶体及其亚基PBA1参与GA对萌发水稻种子糊粉层中贮藏蛋白的调节过程,本研究以水稻杂交种特优128为试验材料,通过采用酶联免疫吸附技术、实时荧光定量PCR技术等方法,检测26S蛋白酶体、20S蛋白酶体及PBA1的活性和OsPBA1转录水平,以及总蛋白含量的变化。结果表明:GA明显促进糊粉层细胞中贮藏蛋白的降解,加快水稻种子的萌发;而在GA合成受阻时,糊粉层细胞中贮藏蛋白的降解进程延缓,从而延迟水稻种子的萌发。正常培养条件下,水稻种子糊粉层中26S蛋白酶体活性和20S蛋白酶体活性的峰值分别出现在6 d和7 d,而OsPBA1表达水平及PBA1活性则在5 d和8 d均呈现峰值。进一步研究表明,GA可以诱导PBA1、20S蛋白酶体及26S蛋白酶体的活性,从而加快种子萌发的进程;而在26S蛋白酶体活性抑制剂MG132处理下,抑制了萌发水稻种子的生长,但提高了20S蛋白酶体和PBA1的活性。以上研究初步揭示了26S蛋白酶体在GA调节水稻种子糊粉层贮藏蛋白降解中的作用及其对种子萌发的影响。Seed germination is a key link for plants to enter the vegetative growth stage.During the germination of rice(Oryza sativa L.)seeds,the aleurone layers synthesize and secrete a series of acid hydrolases(such asα-amylase,protease)to degrade the storage substances in the endosperm and provide nutrition for the growth of rice seedlings.The degradation of storage proteins is inseparable from the role of proteasome and protease in rice seeds.In order to explore the involvement of 26S proteasome,20S proteasome and its subunit PBA1 in the regulation of GA on the storage proteins in the aleurone layers of germinated rice seeds,the rice hybrid Teyou 128 was used as the experimental material.The activity of 26S proteasome,20S proteasome and PBA1,the transcription level of OsPBA1 and the change of total protein content were detected by enzyme-linked immunosorbent assay and real-time fluorescence quantitative PCR.GA significantly promoted the degradation of storage proteins in aleurone cells and accelerated the germination of rice seeds.When GA synthesis was blocked,the degradation process of storage protein in aleurone layer cells was delayed,thus delaying the germination of rice seeds.Under normal culture conditions,the peak values of 26S proteasome activity and 20S proteasome activity in the aleurone layers of rice seeds appeared at 6 d and 7 d,respectively,while the OsPBA1 expression level and PBA1 activity showed peaks at 5 d and 8 d.Further studies showed that GA could induce the activity of PBA1,20S proteasome and 26S proteasome,thereby accelerating the process of seed germination.The 26S proteasome activity inhibitor MG132 inhibited the growth of germinated rice seeds,but increased the activity of 20S proteasome and PBA1.The above studies preliminarily revealed the role of 26S proteasome in GA regulating the deg-radation of storage proteins in rice aleurone layers and its effect on the germination of rice seeds.

关 键 词：GA 蛋白酶体 水稻糊粉层 贮藏蛋白 种子萌发 

分 类 号：S511[农业科学—作物学]