Temperature signaling
Climate change scenarios predict an increase in mean air temperatures and in the frequency, intensity, and length of extreme temperature events in many wine‐growing regions worldwide. Because elevated temperature has detrimental effects on berry growth and composition, it threatens the economic and environmental sustainability of wine production. Using Cabernet Sauvignon fruit‐bearing cuttings, we investigated the effects of high temperature (HT) on grapevine berries through a label‐free shotgun proteomic analysis coupled to a complementary metabolomic study. Among the 2,279 proteins identified, 592 differentially abundant proteins were found in berries exposed to HT. The gene ontology categories “stress,” “protein,” “secondary metabolism,” and “cell wall” were predominantly altered under HT. High temperatures strongly impaired carbohydrate and energy metabolism, and the effects depended on the stage of development and duration of treatment. Transcript amounts correlated poorly with protein expression levels in HT berries, highlighting the value of proteomic studies in the context of heat stress. Furthermore, this work reveals that HT alters key proteins driving berry development and ripening. Finally, we provide a list of differentially abundant proteins that can be considered as potential markers for developing or selecting grape varieties that are better adapted to warmer climates or extreme heat waves.
Flowering time regulation is one of the most important processes in the whole life of flowering plants and FLOWERING LOCUS C (FLC ) is a central repressor of flowering time. However, whether metabolic acetate level affects flowering time is unknown. Here we report that ALDEHYDE DEHYDROGENASE ALDH3F1 plays essential roles in floral transition via FLC‐dependent pathway. In the aldh3f1‐1 mutant, the flowering time was significant earlier than Col‐0 and the FLC expression level was reduced. ALDH3F1 had aldehyde dehydrogenase activity to affect the acetate level in plants, and the amino acids of E214 and C252 are essential for its catalytic activity. Moreover, aldh3f1 mutation reduced acetate level and the total acetylation on histone H3. The H3K9Ac level on FLC locus was decreased in aldh3f1‐1 , which reduced FLC expression. Expression of ALDH3F1 could rescue the decreased H3K9Ac level on FLC, FLC expression and also the early‐flowering phenotype of aldh3f1‐1 , however ALDH3F1 E214A or ALDH3F1 C252A could not. Our findings demonstrate that ALDH3F1 participates in flowering time regulation through modulating the supply of acetate for acetyl‐CoA, which functions as histone acetylation donor to modulate H3K9Ac on FLC locus.
A recent paper by Kidokoro et al. (2020) in The Plant Cell reported a transgene‐dependent transcriptional silencing phenomenon in the dominant ice1‐1 Arabidopsis mutant containing the CBF3‐LUC reporter, and questioned whether ICE1 may regulate CBF genes and may be involved in plant cold response. Here, we evaluate available evidence supporting the involvement of ICE1 in plant cold response, and provide ChIP‐seq data showing ICE1 binding to the promoters of CBF genes and other regulatory genes known to be critical for cold response as well as to the promoters of some COR genes.
The transition to flowering is the most dramatic phase change in flowering plants and is crucial for reproductive success. A complex regulatory network in plants has evolved to perceive and integrate the endogenous and environmental signals. These signals perceived, including day length and temperature, converge to regulate FLOWERING LOCUS T (FT), which encodes a mobile stimulus required for floral induction in Arabidopsis. Despite the discovery of modulation of FT messenger RNA (mRNA) expression by ambient temperature, whether the trafficking of FT protein is controlled in response to changes in growth temperature is so far unknown. Here, we show that FT transport from companion cells to sieve elements is controlled in a temperature‐dependent manner. This process is mediated by multiple C2 domain and transmembrane region proteins (MCTPs) and a soluble N‐ethylmaleimide‐sensitive factor protein attachment protein receptor (SNARE). Our findings suggest that ambient temperatures regulate both FT mRNA expression and FT protein trafficking to prevent precocious flowering at low temperatures and ensure plant reproductive success under favorable environmental conditions.
