Plant Gene Expression Laboratory, CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India.
J Exp Bot. 2013 Aug;64(11):3237-47. doi: 10.1093/jxb/ert162. Epub 2013 Jul 9.
The AP2 domain class of transcription factors is a large family of genes with various roles in plant development and adaptation but with very little functional information in plants other than Arabidopsis. Here, the characterization of an EAR motif-containing transcription factor, SlERF36, from tomato that affects stomatal density, conductance, and photosynthesis is described. Heterologous expression of SlERF36 under the CaMV35S promoter in tobacco leads to a 25-35% reduction in stomatal density but without any effect on stomatal size or sensitivity. Reduction in stomatal density leads to a marked reduction in stomatal conductance (42-56%) as well as transpiration and is associated with reduced CO₂ assimilation rates, reduction in growth, early flowering, and senescence. A prominent adaptive response of SlERF36 overexpressors is development of constitutively high non-photochemical quenching (NPQ) that might function as a protective measure to prevent damage from high excitation pressure. The high NPQ leads to markedly reduced light utilization and low electron transport rates even at low light intensities. Taken together, these data suggest that SlERF36 exerts a negative control over stomatal density and modulates photosynthesis and plant development through its direct or indirect effects.
AP2 结构域转录因子家族是一个庞大的基因家族，在植物发育和适应中具有多种功能，但在除拟南芥以外的植物中，其功能信息非常有限。本文描述了番茄中一个含 EAR 基序的转录因子 SlERF36 的特征，该转录因子影响气孔密度、导度和光合作用。在烟草中，通过 CaMV35S 启动子异源表达 SlERF36 导致气孔密度降低 25-35%，但对气孔大小或敏感性没有影响。气孔密度的降低导致气孔导度显著降低（42-56%），蒸腾作用降低，同时伴随着 CO₂同化率降低、生长减缓、早花和衰老。SlERF36 过表达植株的一个显著适应性反应是产生持续高的非光化学猝灭（NPQ），这可能是一种保护措施，以防止高激发压力造成的损伤。高 NPQ 导致光利用和电子传递速率明显降低，即使在低光强下也是如此。综上所述，这些数据表明 SlERF36 对气孔密度具有负调控作用，并通过其直接或间接作用调节光合作用和植物发育。
