White-brown complex (WBC) transporters, also called half-size ATP binding cassette G (ABCG) transporters, are involved in many biological processes, including seed development; however, the WBC transporters in gra...White-brown complex (WBC) transporters, also called half-size ATP binding cassette G (ABCG) transporters, are involved in many biological processes, including seed development; however, the WBC transporters in grapevines received less attention to date. To reveal the molecular characteristics of WBCs and the connection between WBCs and agronomic traits of stenospermocarpic (seedless) grapevine, we carried out a genomic census and analysis of ovule-associated expression for VvWBC genes in grapevine. We identified 30 VvWBC genes and cloned full-length complementary DNAs (cDNAs) for 20 of these. The tissue or organ-specific expression analysis showed that several VvWBCs exhibited distinct expression patterns with some showing tissue specificity. Twelve VvWBC genes were found to be expressed in the developing ovules. Moreover, the results of quantitative real-time PCR (qRT-PCR) suggested that four of twelve ovule-expressed VvWBCs have distinct expression profiles during the development of ovules between seeded and stenospermocarpic grapevines. These four genes might be involved in ovule abortion. Meanwhile, chromosome mapping, multiple sequence alignments, exon/intron structure analyses and synteny analyses were preformed on VvWBC genes. Our experiments provide a new perspective on the mechanism of stenospermocarpic seedlessness and put forward a framework for further study of WBC transporters.展开更多
Cytokinins(CKs),primarily trans-zeatin(tZ)and isopentenyladenine(iP)types,play critical roles in plant growth,development,and various stress responses.Long-distance transport of tZ-type CKs meidated by Arabidopsis ATP...Cytokinins(CKs),primarily trans-zeatin(tZ)and isopentenyladenine(iP)types,play critical roles in plant growth,development,and various stress responses.Long-distance transport of tZ-type CKs meidated by Arabidopsis ATP-binding cassette transporter subfamily G14(AtABCG14)has been well studied;however,less is known about the biochemical properties of AtABCG14 and its transporter activity toward iP-type CKs.Here we reveal the biochemical properties of AtABCG14 and provide evidence that it is also required for long-distance transport of iP-type CKs.AtABCG14 formed homodimers in human(Homo sapiens)HEK293T,tobacco(Nicotiana tabacum),and Arabidopsis cells.Transporter activity assays of AtABCG14 in Arabidopsis,tobacco,and yeast(Saccharomyces cerevisiae)showed that AtABCG14 may directly transport multiple CKs,including iP-and tZ-type species.AtABCG14 expression was induced by iP in a tZ-type CKdeficient double mutant(cypDM)of CYP735A1 and CYP735A2.The atabcg14 cypDM triple mutant exhibited stronger CK-deficiency phenotypes than cypDM.Hormone profiling,reciprocal grafting,and 2H6-iP isotope tracer experiments showed that root-to-shoot and shoot-to-root long-distance transport of iP-type CKs were suppressed in atabcg14 cypDM and atabcg14.These results suggest that AtABCG14 participates in three steps of the circular long-distance transport of iP-type CKs:xylem loading in the root for shootward transport,phloem unloading in the shoot for shoot distribution,and phloemunloading in the root for root distribution.We found that AtABCG14 displays transporter activity toward multiple CK species and revealed its versatile roles in circular long-distance transport of iP-type CKs.These findings provide newinsights into the transport mechanisms of CKs and other plant hormones.展开更多
基金supported by the National Natural Science Foundation of China (31372023)the earmarked fund for China Agricultural Research System (CARS-30-yz-7)
文摘White-brown complex (WBC) transporters, also called half-size ATP binding cassette G (ABCG) transporters, are involved in many biological processes, including seed development; however, the WBC transporters in grapevines received less attention to date. To reveal the molecular characteristics of WBCs and the connection between WBCs and agronomic traits of stenospermocarpic (seedless) grapevine, we carried out a genomic census and analysis of ovule-associated expression for VvWBC genes in grapevine. We identified 30 VvWBC genes and cloned full-length complementary DNAs (cDNAs) for 20 of these. The tissue or organ-specific expression analysis showed that several VvWBCs exhibited distinct expression patterns with some showing tissue specificity. Twelve VvWBC genes were found to be expressed in the developing ovules. Moreover, the results of quantitative real-time PCR (qRT-PCR) suggested that four of twelve ovule-expressed VvWBCs have distinct expression profiles during the development of ovules between seeded and stenospermocarpic grapevines. These four genes might be involved in ovule abortion. Meanwhile, chromosome mapping, multiple sequence alignments, exon/intron structure analyses and synteny analyses were preformed on VvWBC genes. Our experiments provide a new perspective on the mechanism of stenospermocarpic seedlessness and put forward a framework for further study of WBC transporters.
基金the National Natural Science Foundation of China(31470370 to K.Z.and 32100270 to J.Z.)the Natural Science Foundation of Zhejiang Province(LY22C020003 to J.Z.)C.-J.L.was supported by the DOE Office of Basic Energy Sciences,specifically through the Physical Biosciences Program of the Chemical Sciences,Geosciences and Biosciences Division,under contract DESC0012704.
文摘Cytokinins(CKs),primarily trans-zeatin(tZ)and isopentenyladenine(iP)types,play critical roles in plant growth,development,and various stress responses.Long-distance transport of tZ-type CKs meidated by Arabidopsis ATP-binding cassette transporter subfamily G14(AtABCG14)has been well studied;however,less is known about the biochemical properties of AtABCG14 and its transporter activity toward iP-type CKs.Here we reveal the biochemical properties of AtABCG14 and provide evidence that it is also required for long-distance transport of iP-type CKs.AtABCG14 formed homodimers in human(Homo sapiens)HEK293T,tobacco(Nicotiana tabacum),and Arabidopsis cells.Transporter activity assays of AtABCG14 in Arabidopsis,tobacco,and yeast(Saccharomyces cerevisiae)showed that AtABCG14 may directly transport multiple CKs,including iP-and tZ-type species.AtABCG14 expression was induced by iP in a tZ-type CKdeficient double mutant(cypDM)of CYP735A1 and CYP735A2.The atabcg14 cypDM triple mutant exhibited stronger CK-deficiency phenotypes than cypDM.Hormone profiling,reciprocal grafting,and 2H6-iP isotope tracer experiments showed that root-to-shoot and shoot-to-root long-distance transport of iP-type CKs were suppressed in atabcg14 cypDM and atabcg14.These results suggest that AtABCG14 participates in three steps of the circular long-distance transport of iP-type CKs:xylem loading in the root for shootward transport,phloem unloading in the shoot for shoot distribution,and phloemunloading in the root for root distribution.We found that AtABCG14 displays transporter activity toward multiple CK species and revealed its versatile roles in circular long-distance transport of iP-type CKs.These findings provide newinsights into the transport mechanisms of CKs and other plant hormones.