IBIS-Flora

Angiosperm Flora of India

The impact of photoperiod insensitive Ppd-1a mutations on the photoperiod pathway across the three genomes of hexaploid wheat (Triticum aestivum)

Publication Type:Journal Article
Year of Publication:2012
Authors:Shaw, LM, Turner, AS, Laurie, DA
Journal:The Plant Journal
Volume:71
Issue:1
Date Published:2012
ISBN Number:1365-313X
Keywords:Flowering, gene expression, homoeologues, photoperiod, Ppd-1, Triticum, Triticum aestivum, wheat
Abstract:

Flowering time is a trait that has been extensively altered during wheat domestication, enabling it to be highly productive in diverse environments and providing a rich source of variation for studying adaptation mechanisms. Hexaploid wheat is ancestrally a long-day plant, but many environments require varieties with photoperiod insensitivity (PI) that can flower in short days. PI results from mutations in the Ppd-1 gene on the A, B or D genomes, with individual mutations conferring different degrees of earliness. The basis of this is poorly understood. Using a common genetic background, the effects of A, B and D genome PI mutations on genes of the circadian clock and photoperiod pathway were studied using genome-specific expression assays. Ppd-1 PI mutations did not affect the clock or immediate clock outputs, but affected TaCO1 and TaFT1, with a reduction in TaCO1 expression as TaFT1 expression increased. Therefore, although Ppd-1 is related to PRR genes of the Arabidopsis circadian clock, Ppd-1 affects flowering by an alternative route, most likely by upregulating TaFT1 with a feedback effect that reduces TaCO1 expression. Individual genes in the circadian clock and photoperiod pathway were predominantly expressed from one genome, and there was no genome specificity in Ppd-1 action. Lines combining PI mutations on two or three genomes had enhanced earliness with higher levels, but not earlier induction, of TaFT1, showing that there is a direct quantitative relationship between Ppd-1 mutations, TaFT1 expression and flowering.

URL:http://dx.doi.org/10.1111/j.1365-313X.2012.04971.x
Short Title:The Plant Journal
Fri, 2014-01-24 21:48 -- admin
https://secure.gravatar.com/avatar/5ade1b012674ce3dd941e2ea5dd15cc1.jpg?d=https%3A//flora.indianbiodiversity.org/sites/all/modules/patches/contrib/gravatar/avatar.png&s=100&r=G
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith