Arabidopsis abcbl abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these tr...Arabidopsis abcbl abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcbl and abcbl9 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcbl but not in the abcb19 mutant. Accordingly, endothecium ligniflcation is altered only in abcbl anthers. Both abcbl and abcb1 abcb19 stamens also show altered early development, with asynchronous anther Iocules and a multilayer tapetum. DAPI staining showed that the timing of meiosis is asynchronous in abcbl abcb19 anther Iocules, while only a small percentage of pollen grains are non- viable according to Alexander＇s staining. In agreement, TAM （TARDY ASYNCHRONOUS MEIOSIS）, as well as BAM2 （BARELY ANY MERISTEM）involved in tapetal cell development--areoverexpressed in abcbl abcb19 young flower buds. Corre- spondingly, ABCB1 and ABCB19 mRNA localization supports the observed phenotypes of abcbl and abcbl abcb19 mutant anthers. In conclusion, we provide evidence that auxin transport plays a significant role both in early and late stamen development： ABCB1 plays a major role during anther development, while ABCB19 has a synergistic role.展开更多
基金partially supported by a research grant from MIUR (PRIN) to P.C. and M.C.a research grant to M.C. from the Italian Ministry of Foreign Affairs (Direzione Generale per la Promozione del Sistema Paese, Unità per la cooperazione scientifica e tecnologica bilaterale e multilaterale)
文摘Arabidopsis abcbl abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcbl and abcbl9 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcbl but not in the abcb19 mutant. Accordingly, endothecium ligniflcation is altered only in abcbl anthers. Both abcbl and abcb1 abcb19 stamens also show altered early development, with asynchronous anther Iocules and a multilayer tapetum. DAPI staining showed that the timing of meiosis is asynchronous in abcbl abcb19 anther Iocules, while only a small percentage of pollen grains are non- viable according to Alexander＇s staining. In agreement, TAM （TARDY ASYNCHRONOUS MEIOSIS）, as well as BAM2 （BARELY ANY MERISTEM）involved in tapetal cell development--areoverexpressed in abcbl abcb19 young flower buds. Corre- spondingly, ABCB1 and ABCB19 mRNA localization supports the observed phenotypes of abcbl and abcbl abcb19 mutant anthers. In conclusion, we provide evidence that auxin transport plays a significant role both in early and late stamen development： ABCB1 plays a major role during anther development, while ABCB19 has a synergistic role.
