Kunta Srinivas, Dahan Yardena, Torgeman Shai, Chory Joanne, Burko Yogev
The Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion 7505101, Israel.
Institute of Plant Science and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Plant Cell. 2025 May 9;37(5). doi: 10.1093/plcell/koaf048.
PHYTOCHROME-INTERACTING FACTORs (PIFs) regulate growth-related gene expression in response to environmental conditions. Among their diverse functions in regulating signal responses, PIFs play an important role in thermomorphogenesis (the response to increased ambient temperature) and in the shade avoidance response. While numerous studies have examined the varied roles of PIFs in Arabidopsis (Arabidopsis thaliana), their roles in crop plants remain poorly investigated. This study delves into the conservation of PIFs activity among species by examining their functions in tomato (Solanum lycopersicum) and comparing them to known PIF functions in Arabidopsis using single and higher-order mutants of tomato PIF genes (SlPIFs). We demonstrate that, in contrast to Arabidopsis, PIFs are not required for thermomorphogenesis-induced stem elongation in tomato. In addition, whereas Arabidopsis PIF8 has a minor effect on plant growth, tomato SlPIF8a plays a key role in the low red/far-red (R/FR) response. In contrast, SlPIF4 and SlPIF7s play minor roles in this process. We also investigated the tissue-specific low R/FR response in tomato seedlings and demonstrate that the aboveground organs exhibit a conserved response to low R/FR, which is regulated by SlPIFs. Our findings provide insights into PIF-mediated responses in crop plants, which may guide future breeding strategies to enhance yield under high planting densities.
光敏色素互作因子（PIFs）响应环境条件调节与生长相关的基因表达。在其调节信号响应的多种功能中，PIFs在热形态建成（对环境温度升高的响应）和避荫反应中发挥重要作用。虽然众多研究已探究了PIFs在拟南芥中的不同作用，但其在作物中的作用仍研究不足。本研究通过检测PIFs在番茄中的功能，并利用番茄PIF基因（SlPIFs）的单突变体和高阶突变体，将其与拟南芥中已知的PIF功能进行比较，深入研究了物种间PIFs活性的保守性。我们证明，与拟南芥不同，热形态建成诱导的番茄茎伸长不需要PIFs。此外，拟南芥PIF8对植物生长影响较小，而番茄SlPIF8a在低红光/远红光（R/FR）响应中起关键作用。相比之下，SlPIF4和SlPIF7s在此过程中作用较小。我们还研究了番茄幼苗中组织特异性的低R/FR响应，并证明地上器官对低R/FR表现出保守响应，该响应由SlPIFs调节。我们的研究结果为作物中PIF介导的响应提供了见解，这可能为未来在高种植密度下提高产量的育种策略提供指导。
