李积胜等《New Phytologist》2024年
论文题目：Hydrogen sulfide antagonizes cytokinin to change root system architecture through persulfidation of CKX2 in Arabidopsis
论文作者：Xiuyu Wang, Cuixia Liu, Tian Li, Fangyu Zhou, Haotian Sun, Fali Li , Ying Ma, Honglei Jia, Xiaoyue Zhang, Wei Shi, Chunmei Gong and Jisheng Li
论文摘要：
Hydrogen sulfide (H2S) is an endogenous gaseous signaling molecule, which has been shown to play an important role in plant growth and development by coupling with various phytohormones. However, the relationship between H2S and cytokinin (CTK) and the mechanisms by which H2S and CTK affect root growth remain poorly understood.
Endogenous CTK was analyzed by UHPLC-ESI-MS/MS. Persulfidation of cytokinin oxidase/dehydrogenases (CKXs) was analyzed by mass spectrometry (MS). ckx2/CKX2wild-type (WT), OE CKX2 and ckx2/CKX2Cys(C)62alanine(A) transgenic lines were isolated with the ckx2 background. H2S is linked to CTK content by CKX2, which regulates root system architecture (RSA). Persulfidation at cysteine (Cys)62 residue of CKX2 enhances CKX2 activity, resulting in reduced CTK content. We utilized 35S-LCD/oasa1 transgenic lines to investigate the effect of endogenous H2S on RSA, indicating that H2S reduces the gravitropic set-point angle (GSA), shortens root hairs, and increases the number of lateral roots (LRs). The persulfidation of CKX2Cys62 changes the elongation of cells on the upper and lower flanks of LR elongationzone, confirming that Cys62 of CKX2 is the specificity target of H2S to regulate RSA in vivo.
In conclusion, this study demonstrated that H2S negatively regulates CTK content and affects RSA by persulfidation of CKX2Cys62 in Arabidopsis thaliana.
硫化氢（H2S）是一种内源性气态信号分子，已被证明可通过与各种植物激素的耦合作用在植物生长和发育过程中发挥重要作用。然而，人们对 H2S 和细胞分裂素（CTK）之间的关系以及 H2S 和 CTK 影响根系生长的机制仍然知之甚少。
采用超高效液相色谱-电喷雾离子交换-质谱（UHPLC-ESI-MS/MS）分析了内源 CTK。以ckx2为背景分离出了ckx2/CKX2wild-type (WT)、OE CKX2和ckx2/CKX2Cys(C)62alanine(A)转基因株系。CKX2将H2S与CTK含量联系起来，从而调节根系结构（RSA）。CKX2Cys62的过硫化增强了CKX2的活性，导致CTK含量降低。我们利用35S-LCD/oasa1转基因品系研究了内源 H2S 对 RSA 的影响，结果表明 H2S 会降低重力定点角（GSA）、缩短根毛并增加侧根（LR）的数量。CKX2Cys62的过硫化作用改变了侧根伸长区上下两翼细胞的伸长，证实了 CKX2的Cys62是H2S在体内调控侧根伸长区的特异性靶标。
总之，H2S 通过过硫化拟南芥 CKX2Cys62 来负向调节 CTK 含量并影响 RSA。
文章链接：https://doi.org/10.1111/nph.20122