Divergent expression of cytokinin biosynthesis, signaling and catabolism genes underlying differences in feeding sites induced by cyst and root-knot nematodes
Divergent expression of cytokinin biosynthesis, signaling and catabolism genes underlying differences in feeding sites induced by cyst and root-knot nematodes
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DOI：
10.1111/tpj.13647
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发表时间：
2017-10-01
期刊：
影响因子：
7.2
通讯作者：
Mitchum, Melissa G.
中科院分区：
文献类型：
--
作者：
Dowd, Carola D.;Chronis, Demosthenis;Mitchum, Melissa G.
孢囊线虫和根结线虫是经济上重要的专性寄生虫，具有将根细胞重编程为独特的代谢活性摄食位点的显著能力。以往的研究表明，细胞分裂素在这两种类型的线虫诱导的摄食部位形成的作用，但机制的细节尚未得到描述。利用拟南芥作为寄主植物，我们进行了细胞分裂素基因的比较分析，以响应甜菜胞囊线虫（BCN），Heterodera schachtii，和根结线虫（RKN），南方根结线虫。我们确定了细胞分裂素的生物合成，catalysts和信号转导基因的表达在响应感染BCN和RKN的显着差异，这两个线虫物种的细胞分裂素途径的差异操纵。此外，我们评估了拟南芥组氨酸激酶受体突变株ahk 2/3，ahk 2/4和ahk 3/4响应RKN感染。与我们以前对BCN的研究类似，这些品系对RKN的敏感性显著降低，而不影响线虫的渗透，这表明RKN摄食位点形成需要细胞分裂素信号传导。此外，使用CycB 1;1：GUS/ahk渐渗系的ahk双突变体的分析显示，在BCN和RKN诱导的摄食部位介导细胞周期激活的细胞分裂素受体的对比差异。
Cyst and root-knot nematodes are obligate parasites of economic importance with a remarkable ability to reprogram root cells into unique metabolically active feeding sites. Previous studies have suggested a role for cytokinin in feeding site formation induced by these two types of nematodes, but the mechanistic details have not yet been described. Using Arabidopsis as a host plant species, we conducted a comparative analysis of cytokinin genes in response to the beet cyst nematode (BCN), Heterodera schachtii, and the root-knot nematode (RKN), Meloidogyne incognita. We identified distinct differences in the expression of cytokinin biosynthesis, catabolism and signaling genes in response to infection by BCN and RKN, suggesting differential manipulation of the cytokinin pathway by these two nematode species. Furthermore, we evaluated Arabidopsis histidine kinase receptor mutant lines ahk2/3, ahk2/4 and ahk3/4 in response to RKN infection. Similar to our previous studies with BCN, these lines were significantly less susceptible to RKN without compromising nematode penetration, suggesting a requirement of cytokinin signaling in RKN feeding site formation. Moreover, an analysis of ahk double mutants using CycB1;1:GUS/ahk introgressed lines revealed contrasting differences in the cytokinin receptors mediating cell cycle activation in feeding sites induced by BCN and RKN.