1,720,996 research outputs found
An auxin switch for male fertility
No full textIn autogamous plants, self-pollination is ensured by a timely opening of anthers (dehiscence) and release of mature pollen grains. Auxin plays a paramount role in controlling the correct timing of anther dehiscence. Now, a molecular switch that allows the timely change in auxin level in rice anthers has been unveiled
Rol genes of Agrobacterium rhizogenes cucumopine strain: sequence, effects, and pattern of expression
No full textRegulation and expression of rolB a bacterial gene which controls plant cell differentiation
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Auxin regulates Arabidopsis anther dehiscence, pollen maturation, and filament elongation
No full textWe provide evidence on the localization, synthesis, transport, and effects of auxin on the processes occurring late in Arabidopsis thaliana stamen development: anther dehiscence, pollen maturation, and preanthesis filament elongation. Expression of auxin-sensitive reporter constructs suggests that auxin effects begin in anthers between the end of meiosis and the bilocular stage in the somatic tissues involved in the first step of dehiscence as well as in the microspores and in the junction region between anther and filament. In situ hybridizations of the auxin biosynthetic genes YUC2 and YUC6 suggest that auxin is synthesized in anthers. In agreement with the timing of auxin effects, the TIR1, AFB1, AFB2, and AFB3 auxin receptor-encoding genes are transcribed in anthers only during late stages of development starting at the end of meiosis. We found that in tir1 afb triple and quadruple mutants, anther dehiscence and pollen maturation occur earlier than in the wild type, causing the release of mature pollen grains before the completion of filament elongation. We also assessed the contribution of auxin transport to late stamen developmental processes. Our results suggest that auxin synthesized in anthers plays a major role in coordinating anther dehiscence and pollen maturation, while auxin transport contributes to the independent regulation of preanthesis filament elongation
Localization of agropine-synthesizing functions in the TR region of the root-inducing plasmid of Agrobacterium rhizogenes 1855
No full textThe region of the Ri plasmid pRi 1855 that encodes agropine synthesis has been identified through its sequence homology with the equivalent genes of the octopine Ti plasmid pTi ACH5. Interestingly the agropine genes lie outside the so-far identified T-DNA of pRi 1855, and are separated from this latter by a long sequence of non integrated plasmid DNA. The presence of this additional T-DNA (TRight DNA) in hairy roots was demonstrated by Southern blot analysis and by the presence of specific transcripts. The genes for agropine synthesis are arranged in the Ri plasmid in a reversed order as compared to their orientation in the Ti plasmid pTi ACH5. © 1985
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