油菜素甾醇和獨(dú)腳金內(nèi)酯調(diào)控水稻中胚軸伸長的細(xì)胞學(xué)機(jī)制
發(fā)布時(shí)間：2018-11-14 18:56
【摘要】：近年來,由于農(nóng)村勞動(dòng)力向城市的轉(zhuǎn)移,具有省時(shí)省工省地省水的水稻直播栽培技術(shù)得到廣泛推廣,直播栽培的成功與否很大程度上取決于種子的頂土出苗能力,而中胚軸的長度是影響種子出土能力的重要因素之一,但是對于它的細(xì)胞學(xué)結(jié)構(gòu)及分子機(jī)制的分析并不清楚,因此我們想要揭示水稻中胚軸伸長的機(jī)制。油菜素甾醇(Brassinosteroids,BRs)是一類甾醇類植物內(nèi)源激素,在調(diào)控植物的生長發(fā)育過程中起著重要作用,已有報(bào)道BR可以促進(jìn)水稻中胚軸的伸長;獨(dú)腳金內(nèi)酯(Strigolactones,SLs)是一類新型的植物內(nèi)源激素,近年來的研究表明,SLs可以抑制水稻中胚軸的伸長,但是BR和SL調(diào)控水稻中胚軸伸長的機(jī)制并不清楚。為了揭示BR和SL如何在細(xì)胞學(xué)水平上調(diào)控水稻中胚軸的伸長,我們對BR和SL相關(guān)突變體及轉(zhuǎn)基因系水稻的中胚軸做了橫切和縱切,根據(jù)前人的研究將中胚軸從形態(tài)學(xué)的上端到下端平均分成上、中、下三個(gè)部分,對生長7天的中胚軸橫切后發(fā)現(xiàn),無論是野生型、突變體或是轉(zhuǎn)基因系,中胚軸越靠下的部分程序化細(xì)胞死亡(PCD)現(xiàn)象越嚴(yán)重,因此縱切時(shí)難以觀察到中胚軸的細(xì)胞結(jié)構(gòu)。我們做了中胚軸的生長動(dòng)態(tài)曲線,發(fā)現(xiàn)中胚軸生長5天即停止伸長,因此縱切時(shí)使用生長5天的中胚軸樣品,這樣就避免了嚴(yán)重的PCD現(xiàn)象。縱切結(jié)果發(fā)現(xiàn),BR信號放大轉(zhuǎn)基因系和SL受體突變體及信號突變體中胚軸每個(gè)部分的細(xì)胞數(shù)目均多于野生型,細(xì)胞大小也更大,而BR受體突變體和BR信號減弱突變體中胚軸每個(gè)部分的細(xì)胞數(shù)目均少于野生型,細(xì)胞大小也更小。為了更進(jìn)一步揭示中胚軸的伸長是細(xì)胞數(shù)目變化的結(jié)果還是細(xì)胞大小變化的結(jié)果或是二者共同作用的結(jié)果,我們通過貢獻(xiàn)率的計(jì)算得出:水稻中胚軸的伸長主要是細(xì)胞數(shù)目的變化(即細(xì)胞分裂)造成的。通過在細(xì)胞學(xué)水平上對BR和SL調(diào)控中胚軸伸長的研究,為進(jìn)一步揭示BR和SL調(diào)控水稻中胚軸伸長的分子機(jī)制提供細(xì)胞學(xué)基礎(chǔ),并為有效地改變水稻中胚軸伸長的性狀、適應(yīng)直播栽培技術(shù)提供理論基礎(chǔ)。
[Abstract]:In recent years, because of the transfer of rural labor force to the city, the technology of rice direct seeding with time-saving, labor-saving, land-saving and water-saving has been widely popularized. The success of direct seeding depends to a great extent on the emergence ability of the top soil of the seeds. The length of mesocotyls is one of the important factors affecting the ability of seed unearthed, but the analysis of its cytological structure and molecular mechanism is not clear, so we want to reveal the mechanism of elongation of rice mesocotyls. Brassinosterol (Brassinosteroids,BRs) is a kind of phytosterol endogenous hormone, which plays an important role in regulating the growth and development of plants. It has been reported that BR can promote the elongation of rice mesocotyls. Monogolide (Strigolactones,SLs) is a new type of plant endogenous hormone. Recent studies have shown that SLs can inhibit the elongation of rice mesocotyls, but the mechanism of BR and SL regulating the elongation of rice mesocotyls is not clear. In order to reveal how BR and SL regulate the elongation of rice mesocotyls at cytological level, crosscutting and longitudinal cutting of BR and SL related mutants and mesocotyl of transgenic rice were carried out. According to the previous studies, the mesocotyl was divided from the upper end to the lower end of the morphology, and the middle and the lower parts were divided into three parts. After crosscutting the mesocotyl for 7 days, it was found that whether it was wild type, mutant or transgenic line, The lower the mesocotyls, the more programmed cell death (PCD) is, so it is difficult to observe the cellular structure of the mesocotyls during longitudinal cutting. We have made the growth dynamic curve of mesocotyl and found that the elongation of mesocotyls stopped at 5 days, so we used the mesocotyl sample which grew for 5 days to avoid the serious PCD phenomenon. The results of longitudinal cutting showed that the number of cells in each part of the cotyledon of BR signal amplified transgenic lines, SL receptor mutants and signal mutants was more than that of wild type, and the cell size was larger. However, the number of cells in each part of the hypocotyls of BR receptor mutants and BR signal attenuated mutants was less than that of wild type, and the cell size was much smaller. To further reveal whether the elongation of the mesocotyls is the result of a change in the number of cells, a change in cell size, or a combination of the two. We calculated the contribution rate: the elongation of rice mesocotyls was mainly caused by the change of cell number (that is, cell division). Through the study of BR and SL regulating the elongation of mesocotyls at the cytological level, this paper provides a cytological basis for further revealing the molecular mechanism of BR and SL regulating the elongation of rice mesocotyls, and effectively changes the characters of the elongation of rice mesocotyls. To adapt to direct seeding cultivation technology to provide a theoretical basis.
【學(xué)位授予單位】：華中農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S511
[Abstract]:In recent years, because of the transfer of rural labor force to the city, the technology of rice direct seeding with time-saving, labor-saving, land-saving and water-saving has been widely popularized. The success of direct seeding depends to a great extent on the emergence ability of the top soil of the seeds. The length of mesocotyls is one of the important factors affecting the ability of seed unearthed, but the analysis of its cytological structure and molecular mechanism is not clear, so we want to reveal the mechanism of elongation of rice mesocotyls. Brassinosterol (Brassinosteroids,BRs) is a kind of phytosterol endogenous hormone, which plays an important role in regulating the growth and development of plants. It has been reported that BR can promote the elongation of rice mesocotyls. Monogolide (Strigolactones,SLs) is a new type of plant endogenous hormone. Recent studies have shown that SLs can inhibit the elongation of rice mesocotyls, but the mechanism of BR and SL regulating the elongation of rice mesocotyls is not clear. In order to reveal how BR and SL regulate the elongation of rice mesocotyls at cytological level, crosscutting and longitudinal cutting of BR and SL related mutants and mesocotyl of transgenic rice were carried out. According to the previous studies, the mesocotyl was divided from the upper end to the lower end of the morphology, and the middle and the lower parts were divided into three parts. After crosscutting the mesocotyl for 7 days, it was found that whether it was wild type, mutant or transgenic line, The lower the mesocotyls, the more programmed cell death (PCD) is, so it is difficult to observe the cellular structure of the mesocotyls during longitudinal cutting. We have made the growth dynamic curve of mesocotyl and found that the elongation of mesocotyls stopped at 5 days, so we used the mesocotyl sample which grew for 5 days to avoid the serious PCD phenomenon. The results of longitudinal cutting showed that the number of cells in each part of the cotyledon of BR signal amplified transgenic lines, SL receptor mutants and signal mutants was more than that of wild type, and the cell size was larger. However, the number of cells in each part of the hypocotyls of BR receptor mutants and BR signal attenuated mutants was less than that of wild type, and the cell size was much smaller. To further reveal whether the elongation of the mesocotyls is the result of a change in the number of cells, a change in cell size, or a combination of the two. We calculated the contribution rate: the elongation of rice mesocotyls was mainly caused by the change of cell number (that is, cell division). Through the study of BR and SL regulating the elongation of mesocotyls at the cytological level, this paper provides a cytological basis for further revealing the molecular mechanism of BR and SL regulating the elongation of rice mesocotyls, and effectively changes the characters of the elongation of rice mesocotyls. To adapt to direct seeding cultivation technology to provide a theoretical basis.
【學(xué)位授予單位】：華中農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S511
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
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