Characterization of tomato protein kinases embedding guanylate cyclase catalytic center motif
Characterization of tomato protein kinases embedding guanylate cyclase catalytic center motif
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嵌入鸟苷酸环化酶催化中心基序的番茄蛋白激酶的表征
DOI：
10.1038/s41598-020-61000-7
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发表时间：
2020-03-05
影响因子：
4.6
通讯作者：
Cai, Xin-Zhong
中科院分区：
文献类型：
--
作者：
Rahman, Hafizur;Wang, Xin-Yao;Cai, Xin-Zhong
鸟苷酸环化酶（GC）是催化反应以产生环GMP（cGMP）的酶，环GMP是真核生物中的关键信号分子。然而，系统的鉴定和功能分析的GCs在作物物种尚未进行。本研究系统鉴定了重要经济作物番茄（Solanum lycopersicumL.）并分析了两个推测的番茄GC基因在抗病性中的功能。在番茄基因组中鉴定出99个含有GC催化中心（GC-CC）基序的候选GC。有趣的是，所有这些都是假定的蛋白激酶，在蛋白激酶结构域中嵌入GC-CC基序，因此在此暂命名为GC激酶。拟南芥PEPR的两个同源物SlGC 17和SlGC 18在体外显示出GC活性。SlGC 17和SlGC 18基因的共沉默显著降低了对烟草脆裂病毒、真菌核盘菌（Sclerotinia sclerotiorum）和细菌番茄假单胞菌（Pseudomonasepv.tomato（Pst）DC 3000）的抗性。此外，这两个基因的共沉默减弱了PAMP和DAMP引发的免疫，表现为在SlGC沉默的植物中flg 22、几丁质和AtPep 1-引起的Ca 2+和H2 O2爆发明显减少。此外，这些基因的沉默改变了一组Ca 2+信号转导基因的表达。此外，这些GC激酶基因的共沉默表现出更强的影响，所有上述规定相比，单独沉默。综上所述，我们的研究结果表明GC激酶可能广泛存在于番茄中，并且这两个SlPEPR-GC基因在番茄对多种病原菌的抗性和PAMP/DAMP触发的免疫中起着积极的作用。我们的研究结果提供了深入了解番茄GC-激酶的组成和功能。
Guanylate cyclases (GCs) are enzymes that catalyze the reaction to produce cyclic GMP (cGMP), a key signaling molecule in eukaryotes. Nevertheless, systemic identification and functional analysis of GCs in crop plant species have not yet been conducted. In this study, we systematically identified GC genes in the economically important crop tomato (Solanum lycopersicumL.) and analyzed function of two putative tomato GC genes in disease resistance. Ninety-nine candidate GCs containing GC catalytic center (GC-CC) motif were identified in tomato genome. Intriguingly, all of them were putative protein kinases embedding a GC-CC motif within the protein kinase domain, which was thus tentatively named as GC-kinases here. Two homologs of Arabidopsis PEPRs, SlGC17 and SlGC18 exhibitedin vitroGC activity. Co-silencing ofSlGC17andSlGC18genes significantly reduced resistance to tobacco rattle virus, fungusSclerotinia sclerotiorum, and bacteriumPseudomonas syringaepv.tomato(Pst) DC3000. Moreover, co-silencing of these two genes attenuated PAMP and DAMP-triggered immunity as shown by obvious decrease of flg22, chitin and AtPep1-elicited Ca2+and H2O2burst inSlGC-silenced plants. Additionally, silencing of these genes altered the expression of a set of Ca2+signaling genes. Furthermore, co-silencing of these GC-kinase genes exhibited stronger effects on all above regulations in comparison with individual silencing. Collectively, our results suggest that GC-kinases might widely exist in tomato and the twoSlPEPR-GCgenes redundantly play a positive role in resistance to diverse pathogens and PAMP/DAMP-triggered immunity in tomato. Our results provide insights into composition and functions of GC-kinases in tomato.