淹水胁迫诱导小麦胚乳细胞编程性死亡提前的生理机制和细胞骨架动态研究

发布时间：2018-03-16 13:46

本文选题：淹水　切入点：小麦　出处：《华中农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：前期研究表明,小麦胚乳发育需经历编程性细胞死亡(Programmed cell death,PCD)过程,淹水可加速其进程(Fan et al 2013)。本研究以耐湿品种华麦8号和不耐湿品种华麦9号为材料,探讨了淹水胁迫下小麦胚乳PCD进程提前的生理及细胞学机制。主要结果如下:1.Evans Blue染色结果显示,正常生长的华麦8号和华麦9号胚乳均在花后15 d可检测到PCD现象。淹水处理后,同期生长的胚乳着色更深,PCD进程加剧;与华麦8号相比,华麦9号胚乳PCD进程提前。半薄切片染色结果显示,正常生长的两品种小麦胚乳细胞中淀粉粒和蛋白体均随发育天数增加逐渐增多,淹水可加速淀粉体和蛋白体在胚乳细胞中积累。正常生长的两品种胚乳细胞核分别在花后12 d和15 d发生降解;淹水可加剧同期胚乳核降解过程,并能使华麦9号胚乳细胞核降解提前发生。2.淹水胁迫后,华麦8号颖果含水率下降,胚乳中MDA、H2O2和O2-含量上升,早期发育的胚乳中可溶性糖、可溶性蛋白和脯氨酸含量增加,SOD和CAT活性上升,SOD同工酶谱上新增了SOD1带,CAT同工酶谱上新增了CAT2、CAT5带,且各种CAT同工酶活性均增强;华麦9号胚乳中MDA、O2-、H2O2和可溶性蛋白含量显著上升,SOD和POD活性略有升高,而CAT活性随发育天数的增加呈“降-升-降”的趋势,SOD同工酶变化不大,仅SOD2活性有所上升,而各CAT同工酶活性均上升。3.微管蛋白免疫荧光及免疫电镜结果显示,随着胚乳发育的进行,细胞中微管蛋白荧光信号逐渐增强。胶体金统计分析结果显示,淹水后早期发育的胚乳淀粉质体周围和细胞质囊泡中微管蛋白胶体金数目显著高于对照;花后12 d的胚乳中微管蛋白胶体金颗粒增加,主要分布在淀粉质体周围;花后15 d的胚乳线粒体和淀粉质体周围微管蛋白数量增加,细胞质中分布较少。微丝蛋白免疫荧光及免疫电镜结果显示,正常发育的胚乳细胞中微丝蛋白荧光信号,随发育天数的增加逐渐增强。胶体金统计分析结果显示,淹水处理后,早期发育的胚乳淀粉质体周围和细胞质中微丝蛋白胶体金颗粒显著增加;花后12 d的胚乳线粒体周围微丝蛋白胶体金数目减少;花后15 d,细胞质中仍然分布大量微丝蛋白。综上所述,淹水处理后,华麦8号和华麦9号胚乳中MDA及活性氧含量均上升,造成胚乳PCD进程加剧;早期发育的华麦9号胚乳中活性氧上升幅度大,而其清除能力弱,PCD进程提前。胚乳细胞中养分和淀粉质体迅速积累,细胞骨架可能作为运输轨道,协助胚乳细胞提前完成生命过程,以减轻淹水造成的伤害,其还可能参与淹水胁迫的应急反应,调控胚乳细胞PCD进程。
[Abstract]:Preliminary study shows that the wheat endosperm undergoing programmed cell death (Programmed cell, death, PCD), flooding can speed up the process (Fan et al 2013). In this study, moisture resistant varieties and Huamai 8 moisture resistant varieties Huamai No. 9 as the material, discusses the physiological and cytological mechanism of wheat in advance the PCD process of waterlogging stress. The main results are as follows: 1.Evans Blue staining showed that the normal growth of Huamai No. 8 and No. 9 in the endosperm Huamai 15 d after flowering could be detected by PCD. After flooding, the growth period of endosperm color deeper, increased compared with PCD process; Huamai No. 8, No. 9 Mr endosperm the PCD process in advance. Semi thin sections. Results showed that two varieties of wheat endosperm cell normal growth of starch grains and protein bodies were decreased with the increase in the number of days of development gradually increased, flooding can accelerate starch bodies and protein bodies accumulated in endosperm cells in normal life. Two varieties of endosperm nucleus length are 12 d after flowering and 15 d degradation; flooding may exacerbate the earlier process of endosperm degradation, and can make Huamai No. 9 endosperm nuclei occurred earlier.2. degradation after waterlogging stress, Huamai No. 8 caryopsis water content decreased, endosperm MDA, H2O2 increased and the content of O2-, soluble in early development the endosperm of sugar, soluble protein and proline content increased, the increase of SOD and the activity of CAT, SOD isozymes were added on the SOD1 band, CAT isozyme added CAT2, CAT5, and CAT isoenzyme activity were enhanced; Huamai No. 9 endosperm MDA, O2-, H2O2 increased significantly and the content of soluble protein, SOD and the POD activity increased, while CAT activity increased with the growing days of "down up down" trend, SOD isozyme changed little, only the activity of SOD2 increased, while the CAT isozyme activity increased.3. tubulin immunofluorescence and immunoelectrodes. Microscope results showed that with the development of endosperm cells, tubulin fluorescence signal gradually. Colloidal gold statistical analysis results showed that the number of gold endosperm amyloplast around and cytoplasmic vesicles in tubulin colloid early development after flooding was significantly higher than that of control after anthesis; microtubule associated protein 12 d colloidal gold particles increased in endosperm, mainly the distribution of amyloplasts in the number of flowers around; after 15 d of the mitochondrial and endosperm amyloplast around tubulin increased, less distributed in the cytoplasm. The microfilament protein by immunofluorescence and immunoelectron microscopy showed that the actin protein fluorescence signal of normal development of endosperm cells, increased gradually with the increase of development days. Colloidal gold statistical analysis showed that flooding after treatment, the early endosperm starch plastid development around the microfilaments in the cytoplasm and protein colloidal gold particles increased significantly; 12 d endosperm mitochondria weeks after flower Wai microfilament protein decreased the number of colloidal gold; 15 d after flowering, still a lot of microfilaments in the cytoplasm. The protein distribution in summary, after flooding, the contents of MDA and reactive oxygen species in Huamai No. 8 No. 9 and Mr endosperm were increased, resulting in increased endosperm PCD activity in early development process; Mr No. 9 in endosperm oxygen increase. And the scavenging ability is weak, the PCD process in advance. The rapid accumulation of nutrients and amyloplast in endosperm cells, the cytoskeleton may serve as transport track, assist in endosperm cell life early, in order to reduce the damage caused by flooding, which also may be involved in emergency response to flooding stress, regulation of endosperm cell PCD process.

【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.1

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