The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-spe...The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-specific transcription factor;however,its roles in controlling rice grain appearance quality and the underlying molecular mechanisms have not been fully elucidated.In this study,we demon-strate that OsSPL14 positively regulates appearance quality by controlling grain chalkiness in rice.Genetic analysis revealed that knockdown or knockout of OsSPL14 leads to a chalky grain phenotype,which is associated with significant defects in compound starch granules and notable changes in both starch and protein contents in the endosperm.Transcript analysis identified multiple genes regulated by OsSPL14,including the key granule-bound starch synthase gene Waxy(Wx)and the protein disulfide isomerase-like enzyme-encoding gene PDIL1-1.Both in vitro and in vivo assays demonstrated that OsSPL14 directly binds to the GTAC-box motif in the Wx and PDIL1-1 promoters to enhance their expression.Protein-protein inter-action experiments further revealed that OsSPL14 interacts with the nuclear transcription factor Y(NF-Y)heterodimer OsNF-YB9/YC8-12 to promote the transcription of Wx and PDIL1-1,thereby enhancing rice grain appearance quality.Our findings uncover a novel regulatory pathway controlled by OsSPL14 and pro-vide new insights into the molecular mechanisms underlying rice grain appearance quality,with promising implications for genetic improvement in rice.展开更多
MicroRNAs(miRNAs)are important regulatory elements involved in the regulation of various plant developmental and physiological processes by blocking the expression of target genes.MiR156 and miR529 are two combinatori...MicroRNAs(miRNAs)are important regulatory elements involved in the regulation of various plant developmental and physiological processes by blocking the expression of target genes.MiR156 and miR529 are two combinatorial regulators,which cooperatively target the SQUAMOSA PROMOTER BINDING-LIKE(SPL)family genes.However,there has been no report about the functional conservation and divergence of miR156 and miR529 during plant development to date.In this study,the biological function and relationship of miR156,miR529 and their target Os SPL14 in rice were explored.Overexpression of miR156e or miR529a(miR156e-OE and miR529a-OE)increased the grain size and tiller number but decreased the plant height and panicle length,while an opposite phenotype was observed for their target mimicry(miR156-MIMIC and miR529a-MIMIC)transgenic plants.Stem-loop RT-PCR results revealed ubiquitous expression of miR156 in roots,axillary buds and leaves,while miR529 was preferentially expressed in the panicle.Accordingly,Os SPL14 could be preferentially and precisely cleaved by miR529a in young panicle but by miR156 in vegetative tissues.Transgenic plants generated by the target immune strategy exhibited obvious growth defects upon the blocking of miR156 and/or miR529 function in rice,confirming that both miR156 and miR529 play important roles in controlling rice growth and development.Moreover,the miR156/miR529-Os SPL14 module negatively controlled grain size by regulating the genes associated with grain size and cell cycling,and controlled plant height through a more complicated mechanism.Taken together,our results demonstrate that miR156 and miR529 respectively function dominantly in the vegetative stage and reproductive stage to control rice growth and development by regulating the accumulation of Os SPL14.These findings facilitate a better understanding of the functional conservation and divergence of miR156 and miR529 family in the miRNA combinatorial regulatory network of plants.展开更多
基金supported by grants from the National Natural Science Foundation of China(32472141 and 32101746)the Natural Science Foundation of Hubei Province(JCZRLH202500540,2021CFB033).
文摘The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-specific transcription factor;however,its roles in controlling rice grain appearance quality and the underlying molecular mechanisms have not been fully elucidated.In this study,we demon-strate that OsSPL14 positively regulates appearance quality by controlling grain chalkiness in rice.Genetic analysis revealed that knockdown or knockout of OsSPL14 leads to a chalky grain phenotype,which is associated with significant defects in compound starch granules and notable changes in both starch and protein contents in the endosperm.Transcript analysis identified multiple genes regulated by OsSPL14,including the key granule-bound starch synthase gene Waxy(Wx)and the protein disulfide isomerase-like enzyme-encoding gene PDIL1-1.Both in vitro and in vivo assays demonstrated that OsSPL14 directly binds to the GTAC-box motif in the Wx and PDIL1-1 promoters to enhance their expression.Protein-protein inter-action experiments further revealed that OsSPL14 interacts with the nuclear transcription factor Y(NF-Y)heterodimer OsNF-YB9/YC8-12 to promote the transcription of Wx and PDIL1-1,thereby enhancing rice grain appearance quality.Our findings uncover a novel regulatory pathway controlled by OsSPL14 and pro-vide new insights into the molecular mechanisms underlying rice grain appearance quality,with promising implications for genetic improvement in rice.
基金supported by the National Natural Science Foundation of China(32101746,31872811)Hubei Provincial Natural Science Foundation of China(2021CFB033,2022CFB393)。
文摘MicroRNAs(miRNAs)are important regulatory elements involved in the regulation of various plant developmental and physiological processes by blocking the expression of target genes.MiR156 and miR529 are two combinatorial regulators,which cooperatively target the SQUAMOSA PROMOTER BINDING-LIKE(SPL)family genes.However,there has been no report about the functional conservation and divergence of miR156 and miR529 during plant development to date.In this study,the biological function and relationship of miR156,miR529 and their target Os SPL14 in rice were explored.Overexpression of miR156e or miR529a(miR156e-OE and miR529a-OE)increased the grain size and tiller number but decreased the plant height and panicle length,while an opposite phenotype was observed for their target mimicry(miR156-MIMIC and miR529a-MIMIC)transgenic plants.Stem-loop RT-PCR results revealed ubiquitous expression of miR156 in roots,axillary buds and leaves,while miR529 was preferentially expressed in the panicle.Accordingly,Os SPL14 could be preferentially and precisely cleaved by miR529a in young panicle but by miR156 in vegetative tissues.Transgenic plants generated by the target immune strategy exhibited obvious growth defects upon the blocking of miR156 and/or miR529 function in rice,confirming that both miR156 and miR529 play important roles in controlling rice growth and development.Moreover,the miR156/miR529-Os SPL14 module negatively controlled grain size by regulating the genes associated with grain size and cell cycling,and controlled plant height through a more complicated mechanism.Taken together,our results demonstrate that miR156 and miR529 respectively function dominantly in the vegetative stage and reproductive stage to control rice growth and development by regulating the accumulation of Os SPL14.These findings facilitate a better understanding of the functional conservation and divergence of miR156 and miR529 family in the miRNA combinatorial regulatory network of plants.
