Although nitrogen(N)is known to affect mineral element homeostasis in plants,the molecular mechanisms of interactions between N and other nutrients remain largely unclear.Wereport here that N supply affects ion homeos...Although nitrogen(N)is known to affect mineral element homeostasis in plants,the molecular mechanisms of interactions between N and other nutrients remain largely unclear.Wereport here that N supply affects ion homeostasis inmaize.Berberine hemisulfate staining and a propidiumiodide penetration assay showed that N luxury significantly delayed Casparian strip(CS)formation in maize roots.We further demonstrated that N-mediated CS formation in maize was independent of RBOHF-activated H2O2 production.N luxury induced the expression of ZmmiR528 inwhole roots and root tips.Knockdown and loss-of-function ofZmmiR528 promoted CS formation under both N-luxury and N-deficient conditions.Both ZmMIR528a and ZmMIR528b contribute to early CS formation under different N conditions.RNA-seq and real-time RT-PCR analysis demonstrated that ZmLAC3,but not ZmLAC5,responded to N treatments.Consistent with results obtained with ZmmiR528 TM transgenic maize and mir528a/b loss-of-function mutants,transgenic maize overexpressing ZmLAC3 displayed early CS formation under different N conditions.Under field conditions,K,Ca,Mn,Cu,Mg,and Zn concentrations were greater in the ear leaf of ZmLAC3-overexpressing transgenicmaize than in the wild type.These results indicate that ZmmiR528 affects CS formation in maize by regulating the expression of ZmLAC3,and modification of CS formation has the potential to improve maize quality.展开更多
Many microRNAs (miRNAs) are critical regulators of plant antiviral defense.However,little is known about how these miRNAs respond to virus invasion at the transcriptional level.We previously show that defense against ...Many microRNAs (miRNAs) are critical regulators of plant antiviral defense.However,little is known about how these miRNAs respond to virus invasion at the transcriptional level.We previously show that defense against Rice stripe virus (RSV) invasion entailed a reduction of miR528 accumulation in rice,alleviating miR528-mediated degradation of L-Ascorbate Oxidase (AO) mRNA and bolstering the antiviral activity of AO.Here we show that the miR528-A0 defense module is regulated by the transcription factor SPL9.SPL9 displayed high-affinity binding to specific motifs within the promoter region of miR528 and activated the expression of miR528 gene in vivo.Loss-of-function mutations in SPL9 caused a significant reduction in miR528 accumulation but a substantial increase of AO mRNA,resulting in enhanced plant resistance to RSV.Conversely,transgenic overexpression of SPL9 stimulated the expression of miR528 gene,hence lowering the level of AO mRNA and compromising rice defense against RSV.Importantly,gain in RSV susceptibility did not occur when SPL9 was overexpressed in mir528 loss-of-function mutants,or in transgenic rice expressing a miR528-resistant AO.Taken together,the finding of SPL9-mediated transcriptional activation of miR528 expression adds a new regulatory layer to the miR528-A0 antiviral defense pathway.展开更多
MicroRNAs (miRNAs) are essential regulators,involved in almost all aspects of plant growth and development.In plants,miRNAs prese nt in all an giosperms are regarded as con served miRNAs;in contrast,miRNAs restricted ...MicroRNAs (miRNAs) are essential regulators,involved in almost all aspects of plant growth and development.In plants,miRNAs prese nt in all an giosperms are regarded as con served miRNAs;in contrast,miRNAs restricted to certain lineages (lessconserved) or a single species (species-specific) constitute the non-conserved miRNAs (Cuperus et al.,2011).Different members of a miRNA family usually target similar target genes from a gene family among different species.For in stance,in most analyzed plants,the well-known miR156 family,usually consist!ng of a number of members in a given species,collectively target SQUAMOSA-PROMOTER BINDING PROTEINLIKE (SPL) genes.Gen erally,con served miRNAs target genes encoding transcript factors which function in diverse biological processes.This functional diversity of miRNAs is mainly achieved by the plasticity of their target genes from the same family,such as miR156-targeted SPLs and miR167-targeted ARF (AUXIN RESPONSIVE FACTOR) genes,on regulating distinct downstream gen es.展开更多
基金supported by the National Key Research and Development Program of China(2021YFF1000500)the National Natural Science Foundation of China(grant number 31861143004)the Agricultural Science and Technology Innovation Program of CAAS to WXL.
文摘Although nitrogen(N)is known to affect mineral element homeostasis in plants,the molecular mechanisms of interactions between N and other nutrients remain largely unclear.Wereport here that N supply affects ion homeostasis inmaize.Berberine hemisulfate staining and a propidiumiodide penetration assay showed that N luxury significantly delayed Casparian strip(CS)formation in maize roots.We further demonstrated that N-mediated CS formation in maize was independent of RBOHF-activated H2O2 production.N luxury induced the expression of ZmmiR528 inwhole roots and root tips.Knockdown and loss-of-function ofZmmiR528 promoted CS formation under both N-luxury and N-deficient conditions.Both ZmMIR528a and ZmMIR528b contribute to early CS formation under different N conditions.RNA-seq and real-time RT-PCR analysis demonstrated that ZmLAC3,but not ZmLAC5,responded to N treatments.Consistent with results obtained with ZmmiR528 TM transgenic maize and mir528a/b loss-of-function mutants,transgenic maize overexpressing ZmLAC3 displayed early CS formation under different N conditions.Under field conditions,K,Ca,Mn,Cu,Mg,and Zn concentrations were greater in the ear leaf of ZmLAC3-overexpressing transgenicmaize than in the wild type.These results indicate that ZmmiR528 affects CS formation in maize by regulating the expression of ZmLAC3,and modification of CS formation has the potential to improve maize quality.
基金supported by grants from the Natural Science Foundation of China (31530062,31420103904 and 31722045)Transgenic Research Program (2016ZX08010-001,2016ZX08009003-001)Y.L.,and GARS- 01-06 to 乙H.X.,and Y.L.:ZY was supported by the National Postdoctoral Program for Innovative Talents (BX201700004).
文摘Many microRNAs (miRNAs) are critical regulators of plant antiviral defense.However,little is known about how these miRNAs respond to virus invasion at the transcriptional level.We previously show that defense against Rice stripe virus (RSV) invasion entailed a reduction of miR528 accumulation in rice,alleviating miR528-mediated degradation of L-Ascorbate Oxidase (AO) mRNA and bolstering the antiviral activity of AO.Here we show that the miR528-A0 defense module is regulated by the transcription factor SPL9.SPL9 displayed high-affinity binding to specific motifs within the promoter region of miR528 and activated the expression of miR528 gene in vivo.Loss-of-function mutations in SPL9 caused a significant reduction in miR528 accumulation but a substantial increase of AO mRNA,resulting in enhanced plant resistance to RSV.Conversely,transgenic overexpression of SPL9 stimulated the expression of miR528 gene,hence lowering the level of AO mRNA and compromising rice defense against RSV.Importantly,gain in RSV susceptibility did not occur when SPL9 was overexpressed in mir528 loss-of-function mutants,or in transgenic rice expressing a miR528-resistant AO.Taken together,the finding of SPL9-mediated transcriptional activation of miR528 expression adds a new regulatory layer to the miR528-A0 antiviral defense pathway.
基金funded by the National Key Research and Developmental Program of China (no.2018YFD1000104)the National Natural Science Foundation of China (no.31872063)+1 种基金supported by the Innovation Team Project of the Department of Education of Guangdong Province (no.2016KCXTD 011)the Guangzhou Science and Technology Key Project (no.201804020063).
文摘MicroRNAs (miRNAs) are essential regulators,involved in almost all aspects of plant growth and development.In plants,miRNAs prese nt in all an giosperms are regarded as con served miRNAs;in contrast,miRNAs restricted to certain lineages (lessconserved) or a single species (species-specific) constitute the non-conserved miRNAs (Cuperus et al.,2011).Different members of a miRNA family usually target similar target genes from a gene family among different species.For in stance,in most analyzed plants,the well-known miR156 family,usually consist!ng of a number of members in a given species,collectively target SQUAMOSA-PROMOTER BINDING PROTEINLIKE (SPL) genes.Gen erally,con served miRNAs target genes encoding transcript factors which function in diverse biological processes.This functional diversity of miRNAs is mainly achieved by the plasticity of their target genes from the same family,such as miR156-targeted SPLs and miR167-targeted ARF (AUXIN RESPONSIVE FACTOR) genes,on regulating distinct downstream gen es.
