The single evolutionary origin of chlorinated auxin provides a phylogenetically informative trait in the Fabaceae. (2nd July 2016)

• Record Type: Journal Article
• Authors: Lam, Hong Kiat; Ross, John J.; McAdam, Erin L.; McAdam, Scott A. M.
• Is Part Of: Plant signaling & behavior. Volume 11:Number 7(2016)
• Publication Date: 2016-07-02
• Subjects: Auxin -- chlorinated auxin (4-Cl-IAA -- Cicerae -- evolution -- Fabaceae -- Fabeae -- Ononis -- phylogeny -- seeds -- Trifolieae; Plant ecophysiology -- Periodicals; Plant cellular signal transduction -- Periodicals; Plant cellular signal transduction; Plant ecophysiology; Periodicals; Electronic journals; 581
• DOI: 10.1080/15592324.2016.1197467
• Languages: English
• ISSNs: 1559-2316

Abstract

ABSTRACT: Chlorinated auxin (4-chloroindole-3-acetic acid, 4-Cl-IAA), a highly potent plant hormone, was once thought to be restricted to species of the tribe Fabeae within the Fabaceae, until we recently detected this hormone in the seeds of Medicago, Melilotus and Trifolium species. The absence of 4-Cl-IAA in the seeds of the cultivated species Cicer aeritinum from the Cicerae tribe, immediately basal to the Fabeae and Trifolieae tribes, suggested a single evolutionary origin of 4-Cl-IAA. Here, we provide a more robust phylogenetic placement of the ability to produce chlorinated auxin by screening key species spanning this evolutionary transition. We report no detectable level of 4-Cl-IAA in Cicer echinospermum (a wild relative of C. aeritinum ) and 4 species ( Galega officinalis, Parochetus communis, Astragalus propinquus and A. sinicus ) from tribes or clades more basal or sister to the Cicerae tribe. We did detect 4-Cl-IAA in the dry seeds of 4 species from the genus Ononis that are either basal to the genera Medicago, Melilotus and Trigonella or basal to, but still within, the Fabeae and Trifolieae (ex. Parochetus ) clades. We conclude that the single evolutionary origin of this hormone in seeds can be used as a phylogenetically informative trait within the Fabaceae.