School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
J Integr Plant Biol. 2014 Dec;56(12):1151-63. doi: 10.1111/jipb.12217. Epub 2014 Jul 4.
Sulfur is an essential macronutrient for plants with numerous biological functions. However, the influence of sulfur nutrient availability on the regulation of root development remains largely unknown. Here, we report the response of Arabidopsis thaliana L. root development and growth to different levels of sulfate, demonstrating that low sulfate levels promote the primary root elongation. By using various reporter lines, we examined in vivo IAA level and distribution, cell division, and root meristem in response to different sulfate levels. Meanwhile the dynamic changes of in vivo cysteine, glutathione, and IAA levels were measured. Root cysteine, glutathione, and IAA levels are positively correlated with external sulfate levels in the physiological range, which eventually affect root system architecture. Low sulfate levels also downregulate the genes involved in auxin biosynthesis and transport, and elevate the accumulation of PLT1 and PLT2. This study suggests that sulfate level affects the primary root elongation by regulating the endogenous auxin level and root stem cell niche maintenance.
硫是植物必需的大量营养素，具有多种生物学功能。然而，硫营养供应对根发育调节的影响在很大程度上仍然未知。在这里，我们报告了拟南芥根发育和生长对不同硫酸盐水平的响应，表明低硫酸盐水平促进主根伸长。通过使用各种报告基因系，我们检查了体内生长素水平和分布、细胞分裂和根分生组织对不同硫酸盐水平的反应。同时测量了体内半胱氨酸、谷胱甘肽和生长素水平的动态变化。根半胱氨酸、谷胱甘肽和生长素水平与生理范围内的外部硫酸盐水平呈正相关，最终影响根系结构。低硫酸盐水平还下调了生长素生物合成和运输相关基因的表达，并增加了 PLT1 和 PLT2 的积累。这项研究表明，硫酸盐水平通过调节内源性生长素水平和根干细胞生态位维持来影响主根伸长。
