Senescence,a crucial developmental process in the life cycle of plants,involves programmed destruction of cellular components of leaves.The onset of senescence is synchronized with other developmental processes for su...Senescence,a crucial developmental process in the life cycle of plants,involves programmed destruction of cellular components of leaves.The onset of senescence is synchronized with other developmental processes for successful reproduction since senescence eventually leads to cell death.Arabinosyltransferase FASCIATED AND BRANCHED 2(FAB2)is known to control meristem proliferation.Here,we show that FAB2 could inhibit premature leaf senescence in tomato plants.Both chemically mutagenized and CRISPR-generated fab2 mutants exhibited excessively accelerated senescence,which resulted in sterility.Transcriptome analysis revealed that FAB2 extended leaf longevity by suppressing transcription of genes highly expressed in mature leaves.Transcription of FAB2 was increased in younger leaves,potentially inhibiting premature leaf senescence.The precocious senescence of fab2 mutants was in contrast to fasciated inflorescence(fin)mutants,which carried mutations in a hydroxyproline O-arabinosyltransferase gene,leading to meristem overproliferation.Our observations indicate that complex genetic hierarchy in the cascade of tomato arabinosyltransferases could control different aspects of developmental processes such as stem cell proliferation and senescence.展开更多
Dear Editor,Recent studies have emphasized the importance of editing cis-regulatory elements rather than protein-coding regions to subtly adjust plant traits(Rodrıguez-Leal et al.,2017).However,targeting cis-regulator...Dear Editor,Recent studies have emphasized the importance of editing cis-regulatory elements rather than protein-coding regions to subtly adjust plant traits(Rodrıguez-Leal et al.,2017).However,targeting cis-regulatory elements for mild phenotypic changes has been challenging,often failing to yield significant phenotypic change(Kwon et al.,2020).This underscores the necessity for innovative approaches to secure subtle phenotypic variations.Given the prevalence of gene duplication and redundancy in plant evolution,whereby multiple genes across different families may control a single function(Rodriguez-Leal et al.,2019),our approach involves editing several redundant genes within a family to precisely customize plant traits.展开更多
Xylan, being the second most abundant polysaccharide in dicot wood, is considered to be one of the factors contributing to wood biomass recalcitrance for biofuel production. To better utilize wood as biofuel feedstock...Xylan, being the second most abundant polysaccharide in dicot wood, is considered to be one of the factors contributing to wood biomass recalcitrance for biofuel production. To better utilize wood as biofuel feedstock, it is crucial to functionally characterize all the genes involved in xylan biosynthesis during wood formation. In this report, we investigated roles of poplar families GT43 and GT8 glycosyltransferases in xylan biosynthesis during wood formation. There exist seven GT43 genes in the genome of poplar （Populus trichocarpa）, five of which, namely PtrGT43A, PtrGT43B, PtrGT43C, PtrGT43D, and PtrGT43E, were shown to be highly expressed in the developing wood and their encoded proteins were localized in the Golgi. Comprehensive genetic complementation coupled with chemical analyses demonstrated that overexpression of PtrGT43A/B/E but not PtrGT43C/D was able to rescue the xylan defects conferred by the Arabidopsis irx9 mutant, whereas overexpression of PtrGT43C/D but not PtrGT43A/B/E led to a complementation of the xylan defects in the Arabidopsis irx14 mutant. The essential roles of poplar GT43 members in xylan biosynthesis was further substantiated by RNAi down-regulation of GT43B in the hybrid poplar （Populus alba x tremula） leading to reductions in wall thickness and xylan content in wood, and an elevation in the abundance of the xylan reducing end sequence. Wood digestibility analysis revealed that cellulase digestion released more glucose from the wood of poplar GT43B RNAi lines than the control wood, indicating a decrease in wood biomass recalcitrance. Furthermore, RNAi down-regulation of another poplar wood-associated glycosyltransferase, PoGTSD, was shown to cause decreases in wall thickness and xylan content as well as in the abundance of the xylan reducing end sequence. Together, these findings demonstrate that the poplar GT43 members form two functionally non-redundant groups, namely PtrGT43A/B/E as functional orthologs of Arabidopsis IRX9 and PtrGT43C/D as functional orthologs ofArabidopsis IRX14, all of which are involved in the biosynthesis of xylan backbones, and that the poplar GT8D is essential for the biosynthesis of the xylan reducing end sequence.展开更多
基金funded by National Research Foundation(NRF)of the Ministry of Science and ICT(MSIT),Republic of Korea(Grant Nos.2022R1C1C1002941,2020R1A2C1004273,2020R1A2C1101915)。
文摘Senescence,a crucial developmental process in the life cycle of plants,involves programmed destruction of cellular components of leaves.The onset of senescence is synchronized with other developmental processes for successful reproduction since senescence eventually leads to cell death.Arabinosyltransferase FASCIATED AND BRANCHED 2(FAB2)is known to control meristem proliferation.Here,we show that FAB2 could inhibit premature leaf senescence in tomato plants.Both chemically mutagenized and CRISPR-generated fab2 mutants exhibited excessively accelerated senescence,which resulted in sterility.Transcriptome analysis revealed that FAB2 extended leaf longevity by suppressing transcription of genes highly expressed in mature leaves.Transcription of FAB2 was increased in younger leaves,potentially inhibiting premature leaf senescence.The precocious senescence of fab2 mutants was in contrast to fasciated inflorescence(fin)mutants,which carried mutations in a hydroxyproline O-arabinosyltransferase gene,leading to meristem overproliferation.Our observations indicate that complex genetic hierarchy in the cascade of tomato arabinosyltransferases could control different aspects of developmental processes such as stem cell proliferation and senescence.
基金funded by the National Research Foundation of Korea(NRF)grants fromthe Ministry of Science and ICT(MSIT),Republic of Korea(2022R1C1C1002941 and RS-2024-00407469 to C.-T.K.,2020R1A2C1101915 to S.J.P.,2020R1A2C1004273 to RS-2023-00217064 to W.-J.H.).
文摘Dear Editor,Recent studies have emphasized the importance of editing cis-regulatory elements rather than protein-coding regions to subtly adjust plant traits(Rodrıguez-Leal et al.,2017).However,targeting cis-regulatory elements for mild phenotypic changes has been challenging,often failing to yield significant phenotypic change(Kwon et al.,2020).This underscores the necessity for innovative approaches to secure subtle phenotypic variations.Given the prevalence of gene duplication and redundancy in plant evolution,whereby multiple genes across different families may control a single function(Rodriguez-Leal et al.,2019),our approach involves editing several redundant genes within a family to precisely customize plant traits.
文摘Xylan, being the second most abundant polysaccharide in dicot wood, is considered to be one of the factors contributing to wood biomass recalcitrance for biofuel production. To better utilize wood as biofuel feedstock, it is crucial to functionally characterize all the genes involved in xylan biosynthesis during wood formation. In this report, we investigated roles of poplar families GT43 and GT8 glycosyltransferases in xylan biosynthesis during wood formation. There exist seven GT43 genes in the genome of poplar （Populus trichocarpa）, five of which, namely PtrGT43A, PtrGT43B, PtrGT43C, PtrGT43D, and PtrGT43E, were shown to be highly expressed in the developing wood and their encoded proteins were localized in the Golgi. Comprehensive genetic complementation coupled with chemical analyses demonstrated that overexpression of PtrGT43A/B/E but not PtrGT43C/D was able to rescue the xylan defects conferred by the Arabidopsis irx9 mutant, whereas overexpression of PtrGT43C/D but not PtrGT43A/B/E led to a complementation of the xylan defects in the Arabidopsis irx14 mutant. The essential roles of poplar GT43 members in xylan biosynthesis was further substantiated by RNAi down-regulation of GT43B in the hybrid poplar （Populus alba x tremula） leading to reductions in wall thickness and xylan content in wood, and an elevation in the abundance of the xylan reducing end sequence. Wood digestibility analysis revealed that cellulase digestion released more glucose from the wood of poplar GT43B RNAi lines than the control wood, indicating a decrease in wood biomass recalcitrance. Furthermore, RNAi down-regulation of another poplar wood-associated glycosyltransferase, PoGTSD, was shown to cause decreases in wall thickness and xylan content as well as in the abundance of the xylan reducing end sequence. Together, these findings demonstrate that the poplar GT43 members form two functionally non-redundant groups, namely PtrGT43A/B/E as functional orthologs of Arabidopsis IRX9 and PtrGT43C/D as functional orthologs ofArabidopsis IRX14, all of which are involved in the biosynthesis of xylan backbones, and that the poplar GT8D is essential for the biosynthesis of the xylan reducing end sequence.
