Data_Sheet_4_Insights Into the Regulation of the Expression Pattern of Calvin-Benson-Bassham Cycle Enzymes in C3 and C4 Grasses.PDF

C4 photosynthesis is characterized by the compartmentalization of the processes of atmospheric uptake of CO2 and its conversion into carbohydrate between mesophyll and bundle-sheath cells. As a result, most of the enzymes participating in the Calvin-Benson-Bassham (CBB) cycle, including RubisCO, are highly expressed in bundle-sheath cells. There is evidence that changes in the regulatory sequences of RubisCO contribute to its bundle-sheath-specific expression, however, little is known about how the spatial-expression pattern of other CBB cycle enzymes is regulated. In this study, we use a computational approach to scan for transcription factor binding sites in the regulatory regions of the genes encoding CBB cycle enzymes, SBPase, FBPase, PRK, and GAPDH-B, of C3 and C4 grasses. We identified potential cis-regulatory elements present in each of the genes studied here, regardless of the photosynthetic path used by the plant. The trans-acting factors that bind these elements have been validated in A. thaliana and might regulate the expression of the genes encoding CBB cycle enzymes. In addition, we also found C4-specific transcription factor binding sites in the genes encoding CBB cycle enzymes that could potentially contribute to the pathway-specific regulation of gene expression. These results provide a foundation for the functional analysis of the differences in regulation of genes encoding CBB cycle enzymes between C3 and C4 grasses.

光合作用的C4类型特征在于大气中CO2的吸收及其在叶肉细胞与维管束鞘细胞之间的转化为碳水化合物的过程被隔室化。因此，在参与卡尔文-本森-巴什姆（CBB）循环的大部分酶中，包括核酮糖-1,5-二磷酸羧化酶（RubisCO），在维管束鞘细胞中表达高度。有证据表明，RubisCO的调控序列的改变对其维管束鞘特异性表达有贡献，然而，关于其他CBB循环酶的空间表达模式调控机制所知甚少。在本研究中，我们采用计算方法扫描C3和C4草本植物中编码CBB循环酶、SBPase、FBPase、PRK和GAPDH-B的基因的调控区域中的转录因子结合位点。我们确定了在每个被研究的基因中存在的潜在顺式调控元件，无论植物所采用的光合途径。这些元件的结合的转座作用因子已在拟南芥中验证，并可能调节编码CBB循环酶的基因的表达。此外，我们还发现在编码CBB循环酶的基因中存在C4特异的转录因子结合位点，这些位点可能对基因表达的途径特异性调控做出贡献。这些结果为分析C3和C4草本植物中编码CBB循环酶的基因调控差异的功能分析提供了基础。