Auxin Biosynthesis and Its Role in Plant Development

Abstract

Indole-3-acetic acid (IAA), the main auxin in higher plants, has profound effects on plant growth and development. Both plants and some plant pathogens can produce IAA to modulate plant growth. While the genes and biochemical reactions for auxin biosynthesis in some plant pathogens are well understood, elucidation of the mechanisms by which plants produce auxin has proven to be difficult. So far, no complete pathway of de novo auxin biosynthesis in plants has been firmly established. However, recent studies have led to the discoveries of several genes in tryptophan dependent auxin biosynthesis pathways. Recent findings have also revealed that local auxin biosynthesis plays essential roles in many developmental processes including gametogenesis, embryogenesis, seedling growth, vascular patterning, and flower development. In this review, I summarize the recent advances in dissecting auxin biosynthetic pathways and how the understanding of auxin biosynthesis provides a different angle for analyzing the mechanisms of plant development.

ER-localized auxin transporter PIN8 regulates auxin homeostasis and male gametophyte development in Arabidopsis

“…A crucial aspect of auxin action is its graded distribution (auxin gradients) that depends on local auxin biosynthesis [14][15][16] and directional, intercellular auxin transport 7,17,18 . The polar auxin transport has an essential role in most auxin-regulated processes and is mediated by auxin influx proteins from the AUX1/LAX family 19 , by PIN auxin efflux proteins 20 and by homologues of the ABCB multiple drug resistance transporters 21,22 .…”

Suppression of Arabidopsis flowering by near‐null magnetic field is mediated by auxin

“…Auxin plays a profound role in regulation of almost all processes of plant growth and development including flowering [Zhao, 2010]. Expression of flowering-related gene, LFY, can be induced by auxin [Yamaguchi et al, 2013;Holt et al, 2014].…”

“…Expression of flowering-related gene, LFY, can be induced by auxin [Yamaguchi et al, 2013;Holt et al, 2014]. Deficiency of auxin in plant leads to delay of flowering or defect in floral development [Benkova et al, 2003;Heisler et al, 2005;Zhao, 2010]. Moreover, changes in transport of auxin and auxin signaling also affect Arabidopsis flowering [Sessions and Zambryski, 1995;Li et al, 2009].…”

Assessment of Rice Associated Bacterial Ability to Enhance Rice Seed Germination and Rice Growth Promotion

“…Production of phytohormones is one of the important mechanism and indole-3 acetic acid (IAA), which is a member of native auxin, is a common metabolism produced by several beneficial bacteria 31 . Indole-3 acetic acid stimulates cell elongation through enhancement of cell osmotic contents and cell wall synthesis, permeability of water into cell, decrease in wall pressure and inducing protein synthesis, flowering and fruiting 2 . Solubilization of phosphate is one of the other important mechanism the PGPB uses to enhance growth of host plant.…”