Table_1_Characteristics and candidate genes associated with excellent stalk strength in maize (Zea mays L.).docx

Lodging is a major problem in maize production, which seriously affects yield and hinders mechanized harvesting. Improving stalk strength is an effective way to improve lodging. The maize inbred line Jing2416 (J2416) was an elite germplasm in maize breeding which had strong stalk mechanical strength. To explore the characteristics its stalk strength, we conducted physiological, metabolic and transcriptomic analyses of J2416 and its parents Jing24 (J24) and 5237. At the kernel dent stage, the stalk rind penetrometer strength of J2416 was significantly higher than those of its two parents in multiple environments. The rind thickness, sclerenchyma tissue thickness, and cellulose, hemicellulose, and lignin contents of J2416 were significantly higher than those of its parents. Based on the significant differences between J2416 and 5237, we detected metabolites and gene transcripts showing differences in abundance between these two materials. A total of 212 (68.60%) metabolites and 2287 (43.34%) genes were up-regulated in J2416 compared with 5237. The phenylpropanoid and glycan synthesis/metabolism pathways were enriched in metabolites and genes that were up-regulated in J2416. Twenty-eight of the up-regulated genes in J2416 were involved in lignin, cellulose, and hemicellulose synthesis pathways. These analyses have revealed important physiological characteristics and candidate genes that will be useful for research and breeding of inbred lines with excellent stalk strength.

玉米生产中， lodging（倒伏）问题尤为突出，严重影响了产量并阻碍了机械化收割。增强茎秆抗倒伏能力是提升 lodging 防御效果的有效途径。Jing2416（J2416）玉米自交系在玉米育种领域被视为一类优良的种质资源，其茎秆机械强度显著。为探究其茎秆强度的特性，我们对 J2416 及其亲本 Jing24（J24）和 5237 进行了生理、代谢和转录组分析。在籽粒乳熟期，J2416 在多个环境条件下的茎秆皮层穿透力显著高于其两个亲本。J2416 的皮层厚度、厚壁组织厚度以及纤维素、半纤维素和木质素的含量均显著高于其亲本。基于 J2416 与 5237 之间的显著差异，我们检测到两种材料中丰度差异的代谢物和基因转录本。与 5237 相比，J2416 中共有 212（占 68.60%）种代谢物和 2287（占 43.34%）个基因表达上调。在 J2416 中上调的代谢物和基因主要富集于苯丙素和糖类合成/代谢途径。其中，28 个上调基因参与了木质素、纤维素和半纤维素的合成途径。这些分析揭示了具有重要生理特性的候选基因，这些基因对于研究及培育具有卓越茎秆强度的自交系具有重要意义。