Thermo-Induced Maintenance of Photo-oxidoreductases Underlies Plant Autotrophic Development

Publication date: Available online 6 April 2017
Source:Developmental Cell
Author(s): Jun-Ho Ha, Hyo-Jun Lee, Jae-Hoon Jung, Chung-Mo Park
Chlorophyll biosynthesis enables autotrophic development of developing seedlings. Upon light exposure, the chlorophyll precursor protochlorophyllide produces reactive oxygen species (ROS). Developing seedlings acquire photosynthetic competence through the action of protochlorophyllide oxidoreductases (PORs) that convert protochlorophyllide to chlorophyllide, reducing ROS production that would otherwise induce cellular damage and chlorophyll bleaching. Here, we show that FCA mediates the thermostabilization of PORs to trigger the conversion of protochlorophyllide to chlorophyllide in developing seedlings. FCA also facilitates the thermal induction of POR genes through histone acetylation that promotes the accessibility of RNA polymerases to the gene promoters. The combined action of FCA maintains PORs at warm temperatures, shifting the chlorophyll-ROS balance toward autotrophic development. We propose that the FCA-mediated thermal adaptation of autotrophic development allows developing seedlings to cope with the heat-absorbing soil surface layer under natural conditions. The thermal adaptive mechanism would provide a potential basis for studying crop performance at warm temperatures.

Graphical abstract

Teaser

Ha et al. show that the RNA-binding protein FCA modulates the function of the chlorophyll biosynthesis enzyme POR by suppressing its protein degradation and inducing its gene expression at warm temperatures to achieve thermal adaptation during the autotrophic transition of developing seedlings in Arabidopsis.


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