Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
BMC Plant Biol. 2019 May 16;19(1):201. doi: 10.1186/s12870-019-1811-1.
The kernel row number (KRN) of an ear is an important trait related to yield and domestication in maize. Exploring the underlying genetic mechanisms of KRN has great research significance and application potential.
In the present study, N531 with a KRN of 18-22 and SLN with a KRN of 4-6 were used as the recurrent parent and the donor parent, respectively, to develop two introgression lines (ILs), IL_A and IL_B, both of which have common negative-effect alleles from SLN on chromosomes 1, 5 and 10 and significantly reduced inflorescence meristem (IM) diameter and KRN compared with those of N531. We used RNA-Seq to investigate the transcriptome profiles of 5-mm immature ears of N531, IL_A and IL_B. We identified a total of 2872 differentially expressed genes (DEGs) between N531 and IL_A, 2428 DEGs between N531 and IL_B and 1811 DEGs between IL_A and IL_B. A total of 1252 DEGs were detected as overlapping DEGs, and 89 DEGs were located on the common introgression fragments. Furthermore, three DEGs (Zm00001d013277, Zm00001d015310 and Zm00001d015377) containing three SNPs associated with KRN were identified using regional association mapping.
These results will facilitate our understanding of ear development and provide important candidate genes for further study on KRN.
玉米穗行数（KRN）是一个与产量和驯化有关的重要性状。探索 KRN 的潜在遗传机制具有重要的研究意义和应用潜力。
本研究以穗行数为 18-22 的 N531 为轮回亲本，穗行数为 4-6 的 SLN 为供体亲本，构建了两个导入系（IL），即 IL_A 和 IL_B。这两个 IL 都携带了 SLN 上的共同负效等位基因，导致其穗轴分生组织（IM）直径和 KRN 显著减小。我们使用 RNA-Seq 技术分析了 5mm 未成熟穗的转录组。结果共鉴定到 N531 与 IL_A 之间的 2872 个差异表达基因（DEGs），N531 与 IL_B 之间的 2428 个 DEGs，IL_A 与 IL_B 之间的 1811 个 DEGs。其中共有 1252 个 DEGs 是重叠的，89 个 DEGs 位于共同的导入片段上。此外，通过区域关联作图，我们共鉴定到 3 个与 KRN 相关的包含 3 个 SNP 的 DEGs（Zm00001d013277、Zm00001d015310 和 Zm00001d015377）。
这些结果将有助于我们理解玉米穗的发育，并为进一步研究 KRN 提供重要的候选基因。
