Auxin is synthesized from the amino acid trp in two chemical steps. The first step is the removal of the amino group by the taa family of aminotransferases to produce ipa. Ishida, takanori wakatake, satoko yoshida, yumiko takebayashi, hiroyuki kasahara, eric wafula, claude w. Article pdf available in plant growth regulation 783 july 2015 with 793 reads how we measure reads. A proposed model of local auxin biosynthesis in plant growth and development. Arabidopsis thaliana, auxin biosynthesis, metaxylem, hdzip iii introduction. Although iaa was the first plant hormone identified, the biosynthetic pathway at the genetic level has remained unclear.
The biosynthesis of the main auxin in plants indole3acetic acid iaa has been elucidated recently and is thought to involve the sequential conversion of trp to indole3pyruvic acid to iaa. A auxin produced in microsporocyte and microspores through yucca. Biosynthetic pathways careful investigation into the role played by iaa bio synthesis in somatic embryogenesis has yielded very in triguing information about iaa biosynthesis. At present, six independent pathways of iaa biosynthesis are known, each of which has its own regulation and genetic base. Pdf local auxin biosynthesis mediates plant growth and. Auxin is well known for being involved in many aspects of plant growth and development, but recent findings have revealed that elevated iaa levels or enhanced auxin. The plant hormone auxin, which is predominantly represented by indole3acetic acid iaa, is involved in the regulation of plant growth and development. The plant hormone auxin is a key regulator of plant growth and development. At present, the best defined pathway of auxin biosynthesis is the taayuc route, in which the tryptophan aminotransferases taa and tar and yucca flavindependent monooxygenases produce the auxin indole3acetic acid from tryptophan. Auxin biosynthesis and its role in plant development.
Tryptophandependent auxin biosynthesis is required for hd. Local auxin biosynthesis mediated by a yucca flavin. Local auxin biosynthesis mediated by a yucca flavin monooxygenase regulates haustorium development in the parasitic plant phtheirospermum japonicum juliane k. The main auxin biosynthesis pathway in arabidopsis.
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