Plant trichomes, which are hair-like epidermal structures formed through the polar growth of epidermal cells, widely cover the surfaces of most vascular plants and exhibit diverse morphologies and structures. Specifically, cucumbers are adorned with multicellular, unbranched trichomes, including a distinct type known as spines, located on the surface of the fruit. The presence and density of these fruit spines significantly influence the visual quality of cucumber fruits. However, the key regulatory genes and mechanisms underlying the development of cucumber fruit spines remain poorly understood. In this study, we identified a WUSCHEL-related homeobox (WOX) transcription factor, CsWOX3, in cucumber, which functions as a typical transcriptional repressor and negatively regulates the morphogenesis of cucumber fruit spines. Knockout of CsWOX3 using CRISPR/Cas9 resulted in a significant 2-to-3-fold increase in the diameter of the fruit spine base, while overexpression led to a 17% decrease in diameter compared to the wild type. Additionally, we identified the CsSPL15-CsWOX3-IAA/AUX transcriptional regulatory module and confirmed the physical interaction between CsWOX3 and the RING-finger type E3 ubiquitin ligase CsMIEL1-like during cucumber spine development. Collectively, our study uncovers the role of the WOX transcription factor CsWOX3, thereby enhancing our understanding of the molecular mechanisms governing cucumber fruit spine morphogenesis.
PLANT CELL:西澳大利亚大学发现调控拟南芥生长发育的新机制
EARLY NODULIN 93 (ENOD93) 被认为参与了豆科植物的生物固氮以及禾本科植物对氮素的利用过程。本研究从序列分析入手，发现 ENOD93与N-terminal domain of RESPIRATORY SUPERCOMPLEX FACTOR 2 (RCF2)同源. RCF2调控了cytochrome oxidase (CIV), 影响了酵母线粒体质子梯度的形成。敲除ENOD93会导致拟南芥根系变短以及早花。
ENOD93 并不影响CIV的丰度，也不影响它的活性。但是该基因的缺失会导致依赖ADP的呼吸逐渐下降。在enod93突变体中，线粒体的膜电势显著增高，这是一个依赖CIV的过程，但是ATP的合成速率显著下降，导致ADP的水平显著增高。上述突变体的幼苗呼吸速率显著加快，根系中ADP的水平达到野生型2倍，但是ATP的水平却没有显著提高。
小结：本研究揭示了在拟南芥中存在的一个 ENOD93- HYPOXIA-INDUCED GENE DOMAIN 2 (HIGD2)模块执行了酵母中RCF2的功能。
原文：EARLY NODULIN93 acts via cytochrome c oxidase to alter respiratory ATP production and root growth in plants
