Li Yunfeng, Zhu Jiaqi, Feng Yixuan, Li Zhenfeng, Ren Zheng, Liu Ning, Liu Chaojie, Hao Jinghong, Han Yingyan
Beijing Key Laboratory of New Technology in Agricultural Application, National Demonstration Center for Experimental Plant Production Education, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China.
National Engineering Research Center for Vegetables, Institute of Vegetable Science, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
Front Plant Sci. 2022 Sep 8;13:958833. doi: 10.3389/fpls.2022.958833. eCollection 2022.
Lettuce ( L.) is a leafy vegetable whose edible organs usually are leaf or stems, and thus high-temperature induced bolting followed by flower initiation is an undesirable trait in lettuce production. However, the molecular mechanism that controls lettuce bolting and flowering upon thermal treatments is largely unknown. Here, we identified a Lettuce (), the expression of which was enhanced by heat and auxin treatments. Interestingly, is preferentially expressed in stem apex, suggesting it might be associated with lettuce bolting. Transgenic lettuce overexpressing displayed early bolting and flowering, whereas knockout of dramatically delayed bolting and flowering in lettuce under normal or high temperature conditions. Furthermore, Exogenous application of IAA failed to rescue the late-bolting and -flowering phenotype of mutants. Several floral integrator genes including , , and were co-expressed with in the overexpression and knockout lettuce plants. Yeast one-hybrid (Y1H) experiments suggested that LsARF3 could physically interact with the promoter, which was further confirmed by a dual luciferase assay in tobacco leaves. The results indicated that LsARF3 might directly modulate the expression of in lettuce. Therefore, these results demonstrate that could promote lettuce bolting in response to the high temperature by directly or indirectly activating the expression of floral genes such as which provides new insights into lettuce bolting in the context of ARFs signaling and heat response.
生菜（L.）是一种叶菜类蔬菜，其可食用器官通常是叶片或茎，因此高温诱导抽薹继而开花是生菜生产中不受欢迎的性状。然而，热处理时控制生菜抽薹和开花的分子机制很大程度上尚不清楚。在此，我们鉴定出一个生菜基因（），其表达受热和生长素处理增强。有趣的是，该基因在茎尖优先表达，表明它可能与生菜抽薹有关。过表达该基因的转基因生菜表现出早期抽薹和开花，而在正常或高温条件下敲除该基因显著延迟了生菜的抽薹和开花。此外，外源施加吲哚 - 3 - 乙酸（IAA）未能挽救该基因敲除突变体的晚抽薹和晚开花表型。包括、和在内的几个花整合基因在过表达和基因敲除的生菜植株中与该基因共表达。酵母单杂交（Y1H）实验表明LsARF3可与该基因的启动子发生物理相互作用，烟草叶片中的双荧光素酶测定进一步证实了这一点。结果表明LsARF3可能直接调节生菜中该基因的表达。因此，这些结果表明该基因可通过直接或间接激活如等花基因的表达来促进生菜响应高温的抽薹，这为在ARFs信号传导和热响应背景下的生菜抽薹提供了新的见解。
