Institute of Life Science, Jiangsu University, Zhenjiang, 212013, China.
J Integr Plant Biol. 2014 Feb;56(2):133-50. doi: 10.1111/jipb.12127.
Small auxin-up RNAs (SAURs) are the early auxin-responsive genes represented by a large multigene family in plants. Here, we identified 79 SAUR gene family members from maize (Zea mays subsp. mays) by a reiterative database search and manual annotation. Phylogenetic analysis indicated that the SAUR proteins from Arabidopsis, rice, sorghum, and maize had divided into 16 groups. These genes were non-randomly distributed across the maize chromosomes, and segmental duplication and tandem duplication contributed to the expansion of the maize SAUR gene family. Synteny analysis established orthology relationships and functional linkages between SAUR genes in maize and sorghum genomes. We also found that the auxin-responsive elements were conserved in the upstream sequences of maize SAUR members. Selection analyses identified some significant site-specific constraints acted on most SAUR paralogs. Expression profiles based on microarray data have provided insights into the possible functional divergence among members of the SAUR gene family. Quantitative real-time PCR analysis indicated that some of the 10 randomly selected ZmSAUR genes could be induced at least in maize shoot or root tissue tested. The results reveal a comprehensive overview of the maize SAUR gene family and may pave the way for deciphering their function during plant development.
小生长素-up RNA（SAUR）是植物中以大的多基因家族为代表的早期生长素反应基因。在这里，我们通过反复的数据库搜索和手动注释，从玉米（Zea mays subsp. mays）中鉴定出 79 个 SAUR 基因家族成员。系统发育分析表明，拟南芥、水稻、高粱和玉米的 SAUR 蛋白分为 16 组。这些基因在玉米染色体上是非随机分布的，片段复制和串联复制导致了玉米 SAUR 基因家族的扩张。同线性分析建立了玉米和高粱基因组中 SAUR 基因的同源关系和功能联系。我们还发现，生长素反应元件在玉米 SAUR 成员的上游序列中是保守的。选择分析确定了大多数 SAUR 旁系同源物上的一些显著的、特定于位点的约束。基于微阵列数据的表达谱分析为 SAUR 基因家族成员之间的可能功能分化提供了线索。定量实时 PCR 分析表明，随机选择的 10 个 ZmSAUR 基因中的一些至少可以在测试的玉米茎或根组织中诱导。结果全面概述了玉米 SAUR 基因家族，并可能为在植物发育过程中阐明其功能铺平道路。
