Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechan...Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechanism involved in plant growth and development is epigenetic regulation. A highly dynamic epigenome can respond to environmental changes by regulating gene expression. DNA methylation is one of these epigenetic modifications that can alter gene expression in tissue-cultured pineapple plants. The underlying mechanism of such somaclonal variations in pineapple and the epigenetic regulation involvement in somaclonal variations has not been studied. This study performed DNA methylome and transcriptome sequencing of wild-type(WT) and mutant pineapple plants(WS, HW, and TW). We observed altered DNA methylation patterns in chlorophyll development in the mutants. Specifically, we noticed that the methylation levels in the CHG and CHH contexts were lower in the gene body regions compared to the upstream and downstream regions. We identified several thousand differentially methylated regions(DMRs) located at the gene body regions, some of which overlapped with the differentially expressed genes(DEGs). Functional enrichment analyses suggested that these genes were involved in chlorophyll metabolism. Thus, our results revealed that the transcriptional regulation of many chlorophyll metabolic essential genes could be regulated by DNA methylation caused by somaclonal variations and provided insights into epigenetic mechanisms underlying the regulation of chlorosis in pineapple plants.展开更多
The diurnal course of chlorophyll fluorescence parameter and active oxygen metabolism of flag leaves in PEPC transgenic and untransformed rice Kitaake were studied. The results showed that the photosynthetic rate unde...The diurnal course of chlorophyll fluorescence parameter and active oxygen metabolism of flag leaves in PEPC transgenic and untransformed rice Kitaake were studied. The results showed that the photosynthetic rate under high light intensity has been increased by 50% and photoinhibition of photosynthesis in PEPC transgenic was alleviated after the introduction of PEPC gene from maize into rice. It was demonstrated that the increment of photosynthesis in PEPC transgenic was related to the introduction of PEPC gene using specific inhibitor of PEPC. Photoinhibition of photosynthesis in different genotypes exists at noon under natural condition. PEPC transgenic rice exhibited a less decrease in Fv/Fm, a less photoinhibition and a higher efficiency of light energy conversion to chemical energy and lower thermal energy dissipation. These results provided the physiological basis on the mechanism of tolerance to photoinhibition and rice breeding with high photosynthetic efficiency.展开更多
基金supported by the Science and Technology Major Project of Guangxi (Grant No. Guike AA22068096)Guangxi Distinguished Experts Fellowship to YQ, Science and Technology Major Project of Guangxi (Grant No. Guike 2018-266-Z01)+4 种基金Project of Guangxi featured fruit innovation team on pineapple breeding and cultivation post under national modern agricultural industry technology system (Grant No. nycytxgxcxtd-17-05)Science and Technology Program of Fujian Province (Grant No. 2019N5008)Science and technology innovation project of Pingtan Science and Technology Research Institute (Grant Nos. PT2021007, PT2021003)China Postdoctoral Science Foundation (Grant No. 2018M632564)the National Natural Science Foundation of China (31970333, U1605212)。
文摘Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechanism involved in plant growth and development is epigenetic regulation. A highly dynamic epigenome can respond to environmental changes by regulating gene expression. DNA methylation is one of these epigenetic modifications that can alter gene expression in tissue-cultured pineapple plants. The underlying mechanism of such somaclonal variations in pineapple and the epigenetic regulation involvement in somaclonal variations has not been studied. This study performed DNA methylome and transcriptome sequencing of wild-type(WT) and mutant pineapple plants(WS, HW, and TW). We observed altered DNA methylation patterns in chlorophyll development in the mutants. Specifically, we noticed that the methylation levels in the CHG and CHH contexts were lower in the gene body regions compared to the upstream and downstream regions. We identified several thousand differentially methylated regions(DMRs) located at the gene body regions, some of which overlapped with the differentially expressed genes(DEGs). Functional enrichment analyses suggested that these genes were involved in chlorophyll metabolism. Thus, our results revealed that the transcriptional regulation of many chlorophyll metabolic essential genes could be regulated by DNA methylation caused by somaclonal variations and provided insights into epigenetic mechanisms underlying the regulation of chlorosis in pineapple plants.
基金the State Key Basic Research and Development Plan of China(G1998010100)the Key Project of the International Science and Technology Cooperation(2002AA217141).
文摘The diurnal course of chlorophyll fluorescence parameter and active oxygen metabolism of flag leaves in PEPC transgenic and untransformed rice Kitaake were studied. The results showed that the photosynthetic rate under high light intensity has been increased by 50% and photoinhibition of photosynthesis in PEPC transgenic was alleviated after the introduction of PEPC gene from maize into rice. It was demonstrated that the increment of photosynthesis in PEPC transgenic was related to the introduction of PEPC gene using specific inhibitor of PEPC. Photoinhibition of photosynthesis in different genotypes exists at noon under natural condition. PEPC transgenic rice exhibited a less decrease in Fv/Fm, a less photoinhibition and a higher efficiency of light energy conversion to chemical energy and lower thermal energy dissipation. These results provided the physiological basis on the mechanism of tolerance to photoinhibition and rice breeding with high photosynthetic efficiency.