Aquaporins (APQs) belong to the major intrinsic protein superfamily and play a key role in the transport of water and other solutes across cell membranes. Coffea canephora is an evergreen shrub used for making instant coffees. Genome analysis of C. canephora identified 33 putative aquaporin genes assigned to five subfamilies including seven plasma membrane intrinsic proteins (PIP), 9 tonoplast intrinsic proteins (TIP), 11 NOD26-like intrinsic proteins (NIP), 3 small basic intrinsic proteins (SIP), and 3 X intrinsic proteins (XIP). Generally, the AQPs gene structure was conserved within each subfamily, with exon numbers ranging from one to five. The prediction of the aromatic/arginine selectivity filter (ar/R) and Froger’s positions indicated a noticeable difference in substrate specificity between subfamilies. Synteny analysis revealed high conservation of aquaporin genes in coffee. In silico expression analysis of the CcAQPs genes indicated that they were differentially expressed in various tissues. Members of CcPIPs and CcTIPs subfamilies were validated by real-time quantitative analysis in leaves of two genotypes of C. canephora with contrasting responses to water deficit (clone 14: drought-tolerant and clone 109A: drought-susceptible). Under severe water deficit, the relative expression of isoforms of both genes decreased in clone 14 compared with that under the irrigated condition, while clone 109A showed comparatively higher mRNA levels, with the exception of CcPIP1;2 in the stress condition. This study was the first to characterize and validate aquaporin genes in C. canephora in response to water deficit, and the findings may provide insights for biotechnological approaches to increase tolerance to drought.

中文翻译：

---

响应缺水的咖啡中水通道蛋白基因的全基因组鉴定、进化和表达谱

水通道蛋白 (APQ) 属于主要的内在蛋白质超家族，在水和其他溶质跨细胞膜的运输中起关键作用。Coffea canephora 是一种常绿灌木，用于制作速溶咖啡。C. canephora 的基因组分析确定了 33 个假定的水通道蛋白基因，这些基因分配给 5 个亚家族，包括 7 个质膜内在蛋白 (PIP)、9 个液泡膜内在蛋白 (TIP)、11 个 NOD26 样内在蛋白 (NIP)、3 个小的碱性内在蛋白 (SIP) ) 和 3 X 内在蛋白 (XIP)。一般来说，AQPs 基因结构在每个亚科中都是保守的，外显子数从 1 到 5 不等。芳香族/精氨酸选择性过滤器 (ar/R) 和 Froger 位置的预测表明亚家族之间的底物特异性存在显着差异。Synteny 分析揭示了咖啡中水通道蛋白基因的高度保守性。CcAQPs 基因的计算机模拟表达分析表明它们在各种组织中差异表达。CcPIPs 和 CcTIPs 亚科的成员通过对 C. canephora 的两种基因型叶片的实时定量分析进行验证，它们对缺水的反应不同（克隆 14：耐旱和克隆 109A：干旱敏感）。在严重缺水条件下，与灌溉条件相比，克隆14中两种基因亚型的相对表达量均下降，而克隆109A的mRNA水平相对较高，但胁迫条件下的CcPIP1;2除外。这项研究是第一个表征和验证 C. canephora 响应缺水的水通道蛋白基因的研究，