CONSTANS-LIKE 7 regulates branching and shade avoidance response in Arabidopsis

Abstract

Branching is an important trait of plant development regulated by environmental signals. Phytochromes in Arabidopsis mediate branching in response to the changes in the red light:far-red light ratio (R:FR), the mechanisms of which are still elusive. Here it is shown that overexpression of CONSTANS-LIKE 7 (COL7) results in an abundant branching phenotype which could be efficiently suppressed by shade or a simulated shade environment (low R:FR). Moreover, col7 mutants develop shorter hypocotyls and COL7 overexpression lines develop longer hypocotyls in comparison with the wild type in low R:FR, indicating that COL7 acts as an enhancer of the shade avoidance response. In shade or transient low R:FR, transcriptional and post-transcriptional expression levels of COL7 are up-regulated and positively associated with rapid mRNA accumulation of PHYTOCHROME INTERACTING FACTOR 3-LIKE 1 (PIL1), a marker gene of shade avoidance syndrome (SAS). Taken together, the results suggest a dual role for COL7 which promotes branching in high R:FR conditions but enhances SAS in low R:FR conditions.

The CONSTANS‐like 4 transcription factor, AtCOL4, positively regulates abiotic stress tolerance through an abscisic acid‐dependent manner in Arabidopsis

“…For example, whereas AtCOL3 acts as a flowering repressor during short day and long day conditions, AtCOL9 delays flowering during long days, while AtCOL5 can induce flowering during short days (Cheng and Wang ; Datta et al ; Hassidim et al ). AtCOL7 promotes branching in conditions of a high red light to far‐red light ratio, but enhances shade avoidance syndrome in low red light to far‐red light ratio conditions in Arabidopsis (Wang et al ). However, the characteristics and physiological roles of the products of many of the cloned plant COL genes remain unclear.…”

“…An inspection of the current Arabidopsis databases revealed that the expression profiles of many other COL genes are diurnally oscillated (Blasing et al ). Some COL genes have been characterized with reference to functions associated with the regulation of lateral root formation (Datta et al ), branching phenotype, and shade avoidance response (Wang et al ), and the fruit ripening and stress responses in banana fruit (Chen et al ). These results clearly indicate that the CO and COL genes have a wide‐ranging influence on plant development.…”

Phytochrome A signal transduction 1 and CONSTANS‐LIKE 13 coordinately orchestrate shoot branching and flowering in leafy Brassica juncea

“…These results were consistent with those of a previous study on rice under short-day conditions (Sheng et al, 2016), except for the observed increase in shoot branching. Among A. thaliana CONSTANS-LIKE genes, COL7 reportedly regulates branching and the shade avoidance response involving the PHYBmediated pathway, as well as flowering (Wang et al, 2013;Zhang et al, 2014). Additionally, COL12 overexpression in A. thaliana affects plant architecture by increasing the number of rosette branches and decreasing inflorescence height (Ordonez-Herrera et al, 2018).…”

Adaptive Introgression Promotes Fast Adaptation In Oaks Marginal Populations

“…Indeed, several molecular pathways collaborate to promote flowering in higher plants (Moon et al, 2005;He, 2012), which could provide a myriad explanations to the phenology differences in the absence of data from the complex genetic network that regulates flowering. Or else, the COL2 oak gene could be involved in other adaptive function(s) not related to phenology, such as regulation of abiotic stress tolerance through an abscisic acid dependent manner (At-COL4, Min et al, 2015), or regulation of branching patterns and shade avoidance (At-COL7, Wang et al, 2013 (Wolf, 2011). Adaptive introgression of this gene has been inferred in the pair CJAfg-SNEpy, the two oak populations that grow at highest altitude and are exposed to highest solar radiation intensities, further supporting an adaptive role of the PIE082 alleles.…”