The flower-meristem-identity gene APETALA2(AP2), one of class-A genes, is involved in the establishment of the floral meristem and the forming of sepals and petals. Codon usage bias(CUB) identifies differences among s...The flower-meristem-identity gene APETALA2(AP2), one of class-A genes, is involved in the establishment of the floral meristem and the forming of sepals and petals. Codon usage bias(CUB) identifies differences among species, meanwhile dynamic analysis of base composition can identify the molecular mechanisms and evolutionary relationships of a specific gene. In this study, eight coding sequences(CDS) of AP2 gene were selected from different plant species using the Gen Bank database. Their nucleotide composition(GC content), genetic index, relative synonymous codon usage(RSCU) and relative codon usage bias(RCUB) were calculated with R Software to compare codon bias and base composition dynamics of AP2 gene codon usage patterns in different plant species. The results showed that the usage of AP2 gene codons from different plant species were influened by GC bias, especially GC3 s. Overall, base composition analysis indicated that the usage frequency of codon AT in the gene coding sequence was higher than GC among AP2 gene CDS from different plant species. Furthermore, most AP2 gene CDSs ended with AT; AGA, GCU and UGU had relatively high RSCU values as the most dominant codon; the usage characteristic of the AP2 gene codon in Malus domestica was similar to that of Vitis vinifera; Paeonia lactiflora was similar to Paeonia suffruticosa and Solanum lycopersicum was similar to Petunia×hybrida. There was a moderate preference in the usage of AP2 gene codon among different plant species from relatively low frequency of optimal codon(Fop) values and high effective number of codons(ENC) value. This study has revealed the usage characteristics of the AP2 gene codon from the comparision of AP2 gene codon preference and base dynamics in different plant species and provide a platform for further study towards transgenic engineering and codon optimization.展开更多
The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have ...The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have not been studied in great detail.Previous studies identified,using integrated multipleomics analysis,revealed that APETALA2(AP2)is an important candidate gene that modulates type formation of P.lactiflora flowers.To further reveal the expression mechanism of AP2 in P.lactiflora petals,we examined the profile of AP2 expression in the inner and outer petals of‘ZiFengyu’at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis.Based on our data,the AP2 levels in the outer petals were obviously increased,relative to the inner petals.In addition,the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1,thereby promoting bloom stage S2,while declining stage S4.Using chromosome walking,the 2000 bp of the 5′-end upstream promoter region was achieved.This region harbored a CpG island(−665∼−872 bp),with multiple essential transcription factor binding sites(TFBS)such as NF-kappa B,GATA-1,Sp1,and C/EBP.Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the AP2 promoter,thereinto,the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals.Correlation analysis revealed a negative association between the level of methylation(CpG-3,CpG-6),and AP2 mRNA expression.CpG-3 was located on the Sp1 transcription factor binding site.Thus,we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter,thereby regulating AP2 expression.Herein,we examined the role of AP2 in the determination of flower patterns in P.lactiflora.Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in P.lactiflora.展开更多
AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,A...AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,AP2/EREBP转录因子可以分为2个亚族:EREBP亚族(具有1个AP2/ERF结构域)和AP2亚族(具有2个AP2/ERF结构域)。AP2亚族转录因子有调控花、胚珠和种子发育的功能,而EREBP亚族转录因子(包括DREB类和ERF类)的主要功能是调节植物对激素(乙烯和ABA等)、病原和胁迫(低温、干旱及高盐)等的应答反应。本文讨论了AP2/EREBP转录因子在植物发育和胁迫应答中的研究进展。展开更多
Carotenoids are important nutrients for human health that must be obtained from plants since they cannot be biosynthesized by the human body.Dissecting the regulatory mechanism of carotenoid metabolism in plants repre...Carotenoids are important nutrients for human health that must be obtained from plants since they cannot be biosynthesized by the human body.Dissecting the regulatory mechanism of carotenoid metabolism in plants represents the first step toward manipulating carotenoid contents in plants by molecular design breeding.In this study,we determined that SlAP2c,an APETALA2(AP2)family member,acts as a transcriptional repressor to regulate carotenoid biosynthesis in tomato(Solanum lycopersicum).Knockout of SlAP2c in both the“Micro Tom”and“Ailsa Craig”backgrounds resulted in greater lycopene accumulation,whereas overexpression of this gene led to orange-ripe fruit with significantly lower lycopene contents than the wild type.We established that SlAP2c represses the expression of genes involved in lycopene biosynthesis by directly binding to the cis-elements in their promoters.Moreover,SlAP2c relies on its EAR motif to recruit the co-repressors TOPLESS(TPL)2/4 and forms a complex with histone deacetylase(had)1/3,thereby reducing the histone acetylation levels of lycopene biosynthesis genes.Furthermore,SlAP2a,a homolog of SlAP2c,acts upstream of SlAP2c and alleviates the SlAP2c-induced repression of lycopene biosynthesis genes by inhibiting SlAP2c transcription during fruit ripening.Therefore,we identified a transcriptional cascade mediated by AP2 family members that regulates lycopene biosynthesis during fruit ripening in tomato,laying the foundation for the manipulation of carotenoid metabolism in plants.展开更多
We investigated the microRNA172(miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, ...We investigated the microRNA172(miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, manipulation of which could be economically beneficial. Transgenic gloxinia plants, in which miR172 was either overexpressed or suppressed, were generated using Agrobacterium-mediated transformation. They were used to study the effect of altering the expression of this miRNA on time of flowering and to identify its mRNA target. Early or late flowering was observed in transgenic plants in which miR172 was overexpressed or suppressed, respectively. A full-length complementary DNA(cDNA) of gloxinia(Sinningia speciosa) APETALA2-like(SsAP2-like) was identified as a target of miR172. The altered expression levels of miR172 caused up-or down-regulation of SsAP2-like during flower development, which affected the time of flowering. Quantitative real-time reverse transcription PCR analysis of different gloxinia tissues revealed that the accumulation of SsAP2-like was negatively correlated with the expression of miR172 a, whereas the expression pattern of miR172 a was negatively correlated with that of miR156 a. Our results suggest that transgenic manipulation of miR172 could be used as a universal strategy for regulating time of flowering in ornamental plants.展开更多
Plants have evolved a large number of transcription factors（TF）, which are enriched among duplicate genes,highlighting their roles in complex regulatory networks. The APETALA2/EREBP-like genes constitute a large pla...Plants have evolved a large number of transcription factors（TF）, which are enriched among duplicate genes,highlighting their roles in complex regulatory networks. The APETALA2/EREBP-like genes constitute a large plant TF family and participate in development and stress responses. To probe the conservation and divergence of AP2/EREBP genes,we analyzed the duplication patterns of this family in Brassicaceae and identified interacting proteins of representative Arabidopsis AP2/EREBP proteins. We found that many AP2/EREBP duplicates generated early in Brassicaceae history were quickly lost, but many others were retained in all tested Brassicaceae species, suggesting early functional divergence followed by persistent conservation. In addition,the sequences of the AP2 domain and exon numbers were highly conserved in rosids. Furthermore, we used 16 A.thaliana AP2/EREBP proteins as baits in yeast screens and identified 1,970 potential AP2/EREBP-interacting proteins,with a small subset of interactions verified in planta. Many AP2 genes also exhibit reduced expression in an antherdefective mutant, providing a possible link to developmental regulation. The putative AP2-interacting proteins participate in many functions in development and stress responses,including photomorphogenesis, flower development, pathogenesis, drought and cold responses, abscisic acid and auxin signaling. Our results present the AP2/EREBP evolution patterns in Brassicaceae, and support a proposed interaction network of AP2/EREBP proteins and their putative interacting proteins for further study.展开更多
The Ta Q alleles as one of the AP2-like transcription factors in common wheat(Triticum aestivum) play an important role in the evolution of spike characteristics from wild and domesticated emmer to modern wheat cultiv...The Ta Q alleles as one of the AP2-like transcription factors in common wheat(Triticum aestivum) play an important role in the evolution of spike characteristics from wild and domesticated emmer to modern wheat cultivars. Its loss-of-function mutant not only changed threshability and spike architecture but also affected plant height, flowering time, and floret structure. However, the comprehensive functions of Ta AQ and Ta Dq genes in wheat have not been fully elucidated yet. Here, CRISPR/Sp Cas9 was used to edit wheat Ta AQ and Ta Dq. We obtained homozygous plants in the T1 generation with loss of function of only Ta AQ or Ta Dq and simultaneous loss of function of Ta AQ and Ta Dq to analyze the effect of these genes on wheat spikes and floret shapes. The results demonstrated that the Ta AQ-edited plants and the Ta AQ and Ta Dq simultaneously-edited plants were nearly similar in spike architecture, whereas the Ta Dq-edited plants were different from the wild-type ones only in plant height. Moreover, the Ta AQ-edited plants or the Ta AQ and Ta Dq simultaneously-edited plants were more brittle than the wild-type and the Ta Dqedited plants. Based on the expression profiling, we postulated that the VRN1, FUL2, SEP2, SEP5, and SEP6 genes might affect the number of spikelets and florets per spike in wheat by regulating the expression of Ta Q. Combining the results of this report and previous reports, we conceived a regulatory network of wheat traits, including plant height, spike shape, and floral organs, which were influenced by AP2-like family genes. The results achieved in this study will help us to understand the regulating mechanisms of Ta AQ and Ta Dq alleles on wheat floral organs and inflorescence development.展开更多
The seed coat is important for embryo protection, seed hydration, and dispersal. Seed coat composition is also of interest to the agricultural sector, since it impacts the nutritional value for humans and livestock al...The seed coat is important for embryo protection, seed hydration, and dispersal. Seed coat composition is also of interest to the agricultural sector, since it impacts the nutritional value for humans and livestock alike. Although some seed coat genes have been identified, the developmental pathways controlling seed coat development are not completely elucidated, and a global genetic program associated with seed coat development has not been reported. This study uses a combination of genetic and genomic approaches in Arabidopsis thaliana to begin to address these knowledge gaps. Seed coat development is a complex process whereby the integuments of the ovule differentiate into specialized cell types. In Arabidopsis, the outermost layer of cells secretes mucilage into the apoplast and develops a secondary cell wall known as a columella. The layer beneath the epidermis, the palisade, synthesizes a secondary cell wall on its inner tangential side. The innermost layer （the pigmented layer or endothelium） produces proanthocyanidins that condense into tannins and oxidize, giving a brown color to mature seeds. Genetic separation of these cell layers was achieved using the ap2-7 and tt16-1 mutants, where the epidermis/palisade and the endothelium do not develop respectively. This genetic ablation was exploited to examine the developmental programs of these cell types by isolating and collecting seed coats at key tran- sitions during development and performing global gene expression analysis. The data indicate that the developmental programs of the epidermis and the pigmented layer proceed relatively independently. Global expression datasets that can be used for identification of new gene candidates for seed coat development were generated. These dataset provide a comprehensive expression profile for developing seed coats in Arabidopsis, and should provide a useful resource and reference for other seed systems.展开更多
基金supported by the National Natural Science Foundation of China(31372097)the Agricultural Science&Technology Independent Innovation Fund of Jiangsu Province,China(CX(13)2014)
文摘The flower-meristem-identity gene APETALA2(AP2), one of class-A genes, is involved in the establishment of the floral meristem and the forming of sepals and petals. Codon usage bias(CUB) identifies differences among species, meanwhile dynamic analysis of base composition can identify the molecular mechanisms and evolutionary relationships of a specific gene. In this study, eight coding sequences(CDS) of AP2 gene were selected from different plant species using the Gen Bank database. Their nucleotide composition(GC content), genetic index, relative synonymous codon usage(RSCU) and relative codon usage bias(RCUB) were calculated with R Software to compare codon bias and base composition dynamics of AP2 gene codon usage patterns in different plant species. The results showed that the usage of AP2 gene codons from different plant species were influened by GC bias, especially GC3 s. Overall, base composition analysis indicated that the usage frequency of codon AT in the gene coding sequence was higher than GC among AP2 gene CDS from different plant species. Furthermore, most AP2 gene CDSs ended with AT; AGA, GCU and UGU had relatively high RSCU values as the most dominant codon; the usage characteristic of the AP2 gene codon in Malus domestica was similar to that of Vitis vinifera; Paeonia lactiflora was similar to Paeonia suffruticosa and Solanum lycopersicum was similar to Petunia×hybrida. There was a moderate preference in the usage of AP2 gene codon among different plant species from relatively low frequency of optimal codon(Fop) values and high effective number of codons(ENC) value. This study has revealed the usage characteristics of the AP2 gene codon from the comparision of AP2 gene codon preference and base dynamics in different plant species and provide a platform for further study towards transgenic engineering and codon optimization.
基金the National Natural Science Funds(32102411)the Natural Science Foundation of Jiangsu Province of China(BK20200924)+3 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions of China(20KJB210005)Jiangsu Association for Science and Technology Young Scientific and Technological Talents Project-Supported by Yanqing Wu,the Agricultural Science&Technology Independent Innovation Fund of Jiangsu Province(CX[20]3021)the Graduate Innovation Program of Jiangsu Province(XKYCX19_119)the Excellent Doctoral Dissertation Fund of Yangzhou University。
文摘The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have not been studied in great detail.Previous studies identified,using integrated multipleomics analysis,revealed that APETALA2(AP2)is an important candidate gene that modulates type formation of P.lactiflora flowers.To further reveal the expression mechanism of AP2 in P.lactiflora petals,we examined the profile of AP2 expression in the inner and outer petals of‘ZiFengyu’at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis.Based on our data,the AP2 levels in the outer petals were obviously increased,relative to the inner petals.In addition,the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1,thereby promoting bloom stage S2,while declining stage S4.Using chromosome walking,the 2000 bp of the 5′-end upstream promoter region was achieved.This region harbored a CpG island(−665∼−872 bp),with multiple essential transcription factor binding sites(TFBS)such as NF-kappa B,GATA-1,Sp1,and C/EBP.Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the AP2 promoter,thereinto,the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals.Correlation analysis revealed a negative association between the level of methylation(CpG-3,CpG-6),and AP2 mRNA expression.CpG-3 was located on the Sp1 transcription factor binding site.Thus,we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter,thereby regulating AP2 expression.Herein,we examined the role of AP2 in the determination of flower patterns in P.lactiflora.Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in P.lactiflora.
文摘AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,AP2/EREBP转录因子可以分为2个亚族:EREBP亚族(具有1个AP2/ERF结构域)和AP2亚族(具有2个AP2/ERF结构域)。AP2亚族转录因子有调控花、胚珠和种子发育的功能,而EREBP亚族转录因子(包括DREB类和ERF类)的主要功能是调节植物对激素(乙烯和ABA等)、病原和胁迫(低温、干旱及高盐)等的应答反应。本文讨论了AP2/EREBP转录因子在植物发育和胁迫应答中的研究进展。
基金supported in part by the National Natural Science Foundation of China(no.32372780,no.32172643)the Applied Basic Research Category of Science and Technology Program of Sichuan Province(2021YFQ0071,2022YFSY0059-1,2021YFYZ00105-LH)+2 种基金the Technology Innovation and Application Development Program of Chongqing(cstc2021jscx-cylh X0001)the Natural Science Foundation of Sichuan Province,China(2023NSFSC1991)the Institutional Research Funding of Sichuan University(2022SCUNL105)。
文摘Carotenoids are important nutrients for human health that must be obtained from plants since they cannot be biosynthesized by the human body.Dissecting the regulatory mechanism of carotenoid metabolism in plants represents the first step toward manipulating carotenoid contents in plants by molecular design breeding.In this study,we determined that SlAP2c,an APETALA2(AP2)family member,acts as a transcriptional repressor to regulate carotenoid biosynthesis in tomato(Solanum lycopersicum).Knockout of SlAP2c in both the“Micro Tom”and“Ailsa Craig”backgrounds resulted in greater lycopene accumulation,whereas overexpression of this gene led to orange-ripe fruit with significantly lower lycopene contents than the wild type.We established that SlAP2c represses the expression of genes involved in lycopene biosynthesis by directly binding to the cis-elements in their promoters.Moreover,SlAP2c relies on its EAR motif to recruit the co-repressors TOPLESS(TPL)2/4 and forms a complex with histone deacetylase(had)1/3,thereby reducing the histone acetylation levels of lycopene biosynthesis genes.Furthermore,SlAP2a,a homolog of SlAP2c,acts upstream of SlAP2c and alleviates the SlAP2c-induced repression of lycopene biosynthesis genes by inhibiting SlAP2c transcription during fruit ripening.Therefore,we identified a transcriptional cascade mediated by AP2 family members that regulates lycopene biosynthesis during fruit ripening in tomato,laying the foundation for the manipulation of carotenoid metabolism in plants.
基金Project supported by the National Natural Science Foundation of China(Nos.31171615 and 31401913)
文摘We investigated the microRNA172(miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, manipulation of which could be economically beneficial. Transgenic gloxinia plants, in which miR172 was either overexpressed or suppressed, were generated using Agrobacterium-mediated transformation. They were used to study the effect of altering the expression of this miRNA on time of flowering and to identify its mRNA target. Early or late flowering was observed in transgenic plants in which miR172 was overexpressed or suppressed, respectively. A full-length complementary DNA(cDNA) of gloxinia(Sinningia speciosa) APETALA2-like(SsAP2-like) was identified as a target of miR172. The altered expression levels of miR172 caused up-or down-regulation of SsAP2-like during flower development, which affected the time of flowering. Quantitative real-time reverse transcription PCR analysis of different gloxinia tissues revealed that the accumulation of SsAP2-like was negatively correlated with the expression of miR172 a, whereas the expression pattern of miR172 a was negatively correlated with that of miR156 a. Our results suggest that transgenic manipulation of miR172 could be used as a universal strategy for regulating time of flowering in ornamental plants.
基金financial support from the National Natural Science Foundation of China (91131007)funds from Fudan University
文摘Plants have evolved a large number of transcription factors（TF）, which are enriched among duplicate genes,highlighting their roles in complex regulatory networks. The APETALA2/EREBP-like genes constitute a large plant TF family and participate in development and stress responses. To probe the conservation and divergence of AP2/EREBP genes,we analyzed the duplication patterns of this family in Brassicaceae and identified interacting proteins of representative Arabidopsis AP2/EREBP proteins. We found that many AP2/EREBP duplicates generated early in Brassicaceae history were quickly lost, but many others were retained in all tested Brassicaceae species, suggesting early functional divergence followed by persistent conservation. In addition,the sequences of the AP2 domain and exon numbers were highly conserved in rosids. Furthermore, we used 16 A.thaliana AP2/EREBP proteins as baits in yeast screens and identified 1,970 potential AP2/EREBP-interacting proteins,with a small subset of interactions verified in planta. Many AP2 genes also exhibit reduced expression in an antherdefective mutant, providing a possible link to developmental regulation. The putative AP2-interacting proteins participate in many functions in development and stress responses,including photomorphogenesis, flower development, pathogenesis, drought and cold responses, abscisic acid and auxin signaling. Our results present the AP2/EREBP evolution patterns in Brassicaceae, and support a proposed interaction network of AP2/EREBP proteins and their putative interacting proteins for further study.
基金financially supported in part by grants from the Ministry of Agriculture and Rural Affairs of China(2016ZX08009001 and 2016ZX08010004)the Science and Technology Department of Ningxia China(2019BBF02020)the Chinese Academy of Agricultural Sciences(2060302-2-19)。
文摘The Ta Q alleles as one of the AP2-like transcription factors in common wheat(Triticum aestivum) play an important role in the evolution of spike characteristics from wild and domesticated emmer to modern wheat cultivars. Its loss-of-function mutant not only changed threshability and spike architecture but also affected plant height, flowering time, and floret structure. However, the comprehensive functions of Ta AQ and Ta Dq genes in wheat have not been fully elucidated yet. Here, CRISPR/Sp Cas9 was used to edit wheat Ta AQ and Ta Dq. We obtained homozygous plants in the T1 generation with loss of function of only Ta AQ or Ta Dq and simultaneous loss of function of Ta AQ and Ta Dq to analyze the effect of these genes on wheat spikes and floret shapes. The results demonstrated that the Ta AQ-edited plants and the Ta AQ and Ta Dq simultaneously-edited plants were nearly similar in spike architecture, whereas the Ta Dq-edited plants were different from the wild-type ones only in plant height. Moreover, the Ta AQ-edited plants or the Ta AQ and Ta Dq simultaneously-edited plants were more brittle than the wild-type and the Ta Dqedited plants. Based on the expression profiling, we postulated that the VRN1, FUL2, SEP2, SEP5, and SEP6 genes might affect the number of spikelets and florets per spike in wheat by regulating the expression of Ta Q. Combining the results of this report and previous reports, we conceived a regulatory network of wheat traits, including plant height, spike shape, and floral organs, which were influenced by AP2-like family genes. The results achieved in this study will help us to understand the regulating mechanisms of Ta AQ and Ta Dq alleles on wheat floral organs and inflorescence development.
文摘The seed coat is important for embryo protection, seed hydration, and dispersal. Seed coat composition is also of interest to the agricultural sector, since it impacts the nutritional value for humans and livestock alike. Although some seed coat genes have been identified, the developmental pathways controlling seed coat development are not completely elucidated, and a global genetic program associated with seed coat development has not been reported. This study uses a combination of genetic and genomic approaches in Arabidopsis thaliana to begin to address these knowledge gaps. Seed coat development is a complex process whereby the integuments of the ovule differentiate into specialized cell types. In Arabidopsis, the outermost layer of cells secretes mucilage into the apoplast and develops a secondary cell wall known as a columella. The layer beneath the epidermis, the palisade, synthesizes a secondary cell wall on its inner tangential side. The innermost layer （the pigmented layer or endothelium） produces proanthocyanidins that condense into tannins and oxidize, giving a brown color to mature seeds. Genetic separation of these cell layers was achieved using the ap2-7 and tt16-1 mutants, where the epidermis/palisade and the endothelium do not develop respectively. This genetic ablation was exploited to examine the developmental programs of these cell types by isolating and collecting seed coats at key tran- sitions during development and performing global gene expression analysis. The data indicate that the developmental programs of the epidermis and the pigmented layer proceed relatively independently. Global expression datasets that can be used for identification of new gene candidates for seed coat development were generated. These dataset provide a comprehensive expression profile for developing seed coats in Arabidopsis, and should provide a useful resource and reference for other seed systems.
