Department of Biology, University of Washington, Seattle, Washington 98195, USA.
Plant Physiol. 2012 Dec;160(4):2261-70. doi: 10.1104/pp.112.205575. Epub 2012 Oct 16.
The local environment has a substantial impact on early seedling development. Applying excess carbon in the form of sucrose is known to alter both the timing and duration of seedling growth. Here, we show that sucrose changes growth patterns by increasing auxin levels and rootward auxin transport in Arabidopsis (Arabidopsis thaliana). Sucrose likely interacts with an endogenous carbon-sensing pathway via the PHYTOCHROME-INTERACTING FACTOR (PIF) family of transcription factors, as plants grown in elevated carbon dioxide showed the same PIF-dependent growth promotion. Overexpression of PIF5 was sufficient to suppress photosynthetic rate, enhance response to elevated carbon dioxide, and prolong seedling survival in nitrogen-limiting conditions. Thus, PIF transcription factors integrate growth with metabolic demands and thereby facilitate functional equilibrium during photomorphogenesis.
当地环境对早期幼苗发育有重大影响。已知以蔗糖形式施加过量的碳会改变幼苗生长的时间和持续时间。在这里，我们表明蔗糖通过增加生长素水平和向根的生长素运输来改变生长模式在拟南芥（Arabidopsis thaliana）中。蔗糖可能通过 PHYTOCHROME-INTERACTING FACTOR（PIF）转录因子家族与内源碳感应途径相互作用，因为在高二氧化碳中生长的植物显示出相同的依赖 PIF 的生长促进。过表达 PIF5 足以抑制光合作用率，增强对高二氧化碳的响应，并延长在氮限制条件下幼苗的存活时间。因此，PIF 转录因子将生长与代谢需求结合起来，从而在光形态发生过程中促进功能平衡。
