On the cover: Peanut is an important oilseed crop worldwide. What makes peanut plants special is that they flower aboveground but bear seeds belowground. In this issue, Cui et al. (2024) investigated the molecular mechanisms underlying early pod development of peanut fruit by combined analyses of single-nucleus RNA-seq and ATAC-seq datasets. Deeper understanding of cell-type-specific molecular changes and coordinated regulation of gene expression during peanut fruit pod development would contribute to agricultural efforts aimed at improving peanut production. Image by: Xiaoqin Liu and Yuanyuan Cui.
新植物学家：美国俄亥俄州立大学揭示植物耐冷胁迫的新机制
PSEUDORESPONSE REGULATOR7 (PRR7)是拟南芥生物钟系统的一个关键组分，它在植物耐受冷胁迫的过程中发挥负作用。PRR7负调控C-REPEAT BINDING FACTOR1 (CBF1) and COLD-REGULATED 15A (COR15A) 的表达。本研究发现来自拟南芥的HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15)通过泛素化降低PRR7的蛋白丰度。在hos15中PRR7的蛋白水平显著提高, 导致CBFs and COR15A的表达被显著抑制，从而对冷胁迫敏感度显著增加。
小结：本研究揭示了HOS15通过在蛋白水平上负调控PRR7来提高植物耐受冷胁迫的机制。
A working model of the posttranslational regulation of PSEUDORESPONSE REGULATOR7 (PRR7) abundance and enhanced cold tolerance by HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15). At low temperatures, HOS15 promotes the degradation of PRR7 protein through a CULLIN4-based E3 ubiquitin ligase complex (proteasome icon) during the night, resulting in the transcriptional derepression of the cold stress-responsive genes C-REPEAT/DRE BINDING FACTOR 1 (CBF1) and COLD-REGULATED 15A (COR15A). In the hos15 mutant PRR7 levels remain high at night, CBF1 and COR15A levels are repressed, resulting in increased freezing sensitivity (shriveled silhouette in lower panel). ? indicates unknown factor (possibly CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1); see text) that facilitates the stronger HOS15-mediated PRR7 degradation in the dark and cold. Blunt-ended arrows indicate transcriptional repression.
原文：HOS15-mediated turnover of PRR7 enhances freezing tolerance
