Distinct Characteristics of Indole-3-Acetic Acid and XXXX , Two Common Auxins in Plants.

@entity6207 @entity2829 @entity1785 @entity958 @entity12527 @entity3880 @entity50339
The phytohormone auxin plays a central role in many aspects of plant growth and development. IAA is the most studied natural auxin that possesses the property of polar transport in plants. @entity12527 ( @entity3880 ) has also been recognized as a natural auxin for >40 years, but its role in plant growth and development remains unclear. In this study, we show that IAA and @entity3880 have overlapping regulatory roles but distinct transport characteristics as auxins in plants. @entity3880 is widely distributed in vascular and non-vascular plants. Although the biological activities of @entity3880 are lower than those of IAA, the endogenous levels of @entity3880 are much higher than those of IAA in various plant tissues in @entity958 . @entity3880 and @entity6207 can regulate the same set of auxin-responsive genes through the @entity50339 /AFB pathway in @entity958 . IAA actively forms concentration gradients in @entity2829 coleoptiles in response to gravitropic stimulation, whereas @entity3880 does not, indicating that @entity3880 is not actively transported in a polar manner. The induction of the YUCCA (YUC) genes increases @entity3880 metabolite levels in @entity958 , indicating that YUC @entity1785 -containing monooxygenases may play a role in @entity3880 biosynthesis. Our results provide new insights into the regulation of plant growth and development by different types of auxins.
