College of Life Science, Henan Agricultural University, Zhengzhou 450002, PR China.
Library of Henan Agricultural University, Zhengzhou 450002, PR China.
J Plant Physiol. 2018 Jan;220:24-33. doi: 10.1016/j.jplph.2017.10.010. Epub 2017 Nov 10.
Sulfur is an essential macronutrient required for plant growth, development and stress responses. The family of sulfate transporters (SULTRs) mediates the uptake and translocation of sulfate in higher plants. However, basic knowledge of the SULTR gene family in maize (Zea mays L.) is scarce. In this study, a genome-wide bioinformatic analysis of SULTR genes in maize was conducted, and the developmental expression patterns of the genes and their responses to sulfate starvation and abiotic stress were further investigated. The ZmSULTR family includes eight putative members in the maize genome and is clustered into four groups in the phylogenetic tree. These genes displayed differential expression patterns in various organs of maize. For example, expression of ZmSULTR1;1 and ZmSULTR4;1 was high in roots, and transcript levels of ZmSULTR3;1 and ZmSULTR3;3 were high in shoots. Expression of ZmSULTR1;2, ZmSULTR2;1, ZmSULTR3;3, and ZmSULTR4;1 was high in flowers. Also, these eight genes showed differential responses to sulfate deprivation in roots and shoots of maize seedlings. Transcript levels of ZmSULTR1;1, ZmSULTR1;2, and ZmSULTR3;4 were significantly increased in roots during 12-day-sulfate starvation stress, while ZmSULTR3;3 and ZmSULTR3;5 only showed an early response pattern in shoots. In addition, dynamic transcriptional changes determined via qPCR revealed differential expression profiles of these eight ZmSULTR genes in response to environmental stresses such as salt, drought, and heat stresses. Notably, all the genes, except for ZmSULTR3;3, were induced by drought and heat stresses. However, a few genes were induced by salt stress. Physiological determination showed that two important thiol-containing compounds, cysteine and glutathione, increased significantly under these abiotic stresses. The results suggest that members of the SULTR family might function in adaptations to sulfur deficiency stress and adverse growing environments. This study will lay a foundation for better understanding the functional diversity of the SULTR family and exploring genes of interest for genetic improvement of sulfur use efficiency in cereal crop plants.
硫是植物生长、发育和应对胁迫所必需的大量营养元素。硫酸盐转运蛋白（SULTRs）家族介导高等植物中硫酸盐的摄取和转运。然而，关于玉米（Zea mays L.）SULTR 基因家族的基本知识还很缺乏。在这项研究中，对玉米中的 SULTR 基因进行了全基因组生物信息学分析，并进一步研究了这些基因的发育表达模式及其对硫酸盐饥饿和非生物胁迫的响应。ZmSULTR 家族包括玉米基因组中的 8 个假定成员，在系统进化树上聚类为 4 个组。这些基因在玉米的不同器官中表现出不同的表达模式。例如，ZmSULTR1;1 和 ZmSULTR4;1 在根部的表达水平较高，而 ZmSULTR3;1 和 ZmSULTR3;3 在地上部的表达水平较高。ZmSULTR1;2、ZmSULTR2;1、ZmSULTR3;3 和 ZmSULTR4;1 在花中的表达水平较高。此外，这 8 个基因在玉米幼苗的根和地上部对硫酸盐缺乏有不同的响应。在 12 天硫酸盐饥饿胁迫下，ZmSULTR1;1、ZmSULTR1;2 和 ZmSULTR3;4 的转录水平在根部显著增加，而 ZmSULTR3;3 和 ZmSULTR3;5 仅在地上部表现出早期响应模式。此外，通过 qPCR 确定的动态转录变化揭示了这 8 个ZmSULTR 基因在应对盐、干旱和热胁迫等环境胁迫时的差异表达谱。值得注意的是，除了 ZmSULTR3;3 之外，所有基因都被干旱和热胁迫诱导。然而，一些基因被盐胁迫诱导。生理测定表明，两种重要的含硫化合物，半胱氨酸和谷胱甘肽，在这些非生物胁迫下显著增加。结果表明，SULTR 家族的成员可能在适应硫缺乏胁迫和不利的生长环境方面发挥作用。本研究将为更好地理解 SULTR 家族的功能多样性以及探索与谷物作物硫利用效率遗传改良相关的感兴趣基因奠定基础。
