modulates plant development and negatively regulates chilling tolerance in tomato
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
SUMMARY Chilling stress severely restricts tomato cultivation and productivity, yet the mechanisms by which a single regulator integrates photosynthetic efficiency, developmental progression, and chilling tolerance remain to be elucidated. Here, we characterized, a chilling‐inducible B‐box transcription factor in tomato (). SlBBX19 is nucleus‐localized, functions as a negative regulator of vegetative growth and photosynthetic capacity under normal conditions, while simultaneously promoting fruit ripening and suppressing inflorescence branching. Under chilling stress,acts as a negative regulator of chilling tolerance: overexpression exacerbates reactive oxygen species (ROS) accumulation, membrane damage, and suppressespathway activation, whereas knockout lines exhibit enhanced chilling resistance. Transcriptomic and molecular analyses reveal that SlBBX19 directly binds to G‐box elements in the promoters of light‐harvesting chlorophyll a/b‐binding genesandto repress their transcription. Virus‐induced gene silencing of these targets recapitulated the overexpression phenotypes, confirming thatcompromises photosynthetic efficiency and chilling tolerance primarily throughdownregulation. Collectively, our findings establishas a key integrator of development and environmental acclimation, revealing a novel regulatory module that links photosynthetic antenna dynamics to chilling stress adaptation. This work may provide a promising genetic target for engineering chilling‐tolerant and p
Abstract
SUMMARY Chilling stress severely restricts tomato cultivation and productivity, yet the mechanisms by which a single regulator integrates photosynthetic efficiency, developmental progression, and chilling tolerance remain to be elucidated. Here, we characterized, a chilling‐inducible B‐box transcription factor in tomato (). SlBBX19 is nucleus‐localized, functions as a negative regulator of vegetative growth and photosynthetic capacity under normal conditions, while simultaneously promoting fruit ripening and suppressing inflorescence branching. Under chilling stress,acts as a negative regulator of chilling tolerance: overexpression exacerbates reactive oxygen species (ROS) accumulation, membrane damage, and suppressespathway activation, whereas knockout lines exhibit enhanced chilling resistance. Transcriptomic and molecular analyses reveal that SlBBX19 directly binds to G‐box elements in the promoters of light‐harvesting chlorophyll a/b‐binding genesandto repress their transcription. Virus‐induced gene silencing of these targets recapitulated the overexpression phenotypes, confirming thatcompromises photosynthetic efficiency and chilling tolerance primarily throughdownregulation. Collectively, our findings establishas a key integrator of development and environmental acclimation, revealing a novel regulatory module that links photosynthetic antenna dynamics to chilling stress adaptation. This work may provide a promising genetic target for engineering chilling‐tolerant and physiologically optimized tomato varieties. Significance Statement Chilling stress severely limits tomato production, yet how plant development and chilling tolerance are coordinately regulated remains poorly understood. We identify the B‐box transcription factor SlBBX19 as a key regulator linking photosynthetic antenna gene expression with plant development and chilling responses, providing a promising genetic target for improving chilling tolerance and productivity in tomato. short