Chu Jin, Xu Han, Dong Hai, Xuan Yuan Hu
Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang, 110161, China.
College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China.
Rice (N Y). 2021 Jul 2;14(1):60. doi: 10.1186/s12284-021-00505-9.
Sheath blight disease (ShB) is a destructive disease affecting rice production. Previously, we have reported that Loose Plant Architecture 1 (LPA1) promotes resistance to ShB. However, the mechanisms by which LPA1 confers resistance against this disease have not been extensively investigated. Notably, interactors that regulate LPA-1 activity remain elusive.
In this study, we identified the interaction of kinesin-like protein (KLP) with LPA1 in the nucleus of rice cells by yeast two-hybrid, bimolecular fluorescent complimentary (BiFC), and co-immunoprecipitation (co-IP) assays. To investigate the role of KLP in promoting resistance to ShB, wild-type, klp mutant, and KLP overexpressor (KLP OX) rice plants were inoculated with Rhizoctonia solani AG1-IA. The results indicated that, compared with the wild-type control, klp mutants were more susceptible while KLP OX plants were less susceptible to ShB. Since LPA1 transcriptionally activates PIN-FORMED 1a (PIN1a), we examined the expression of 8 related PIN genes. The results showed that only the expression of PIN1a and PIN3b coincided with KLP expression levels. In addition, a chromatin immunoprecipitation (ChIP) assay showed that KLP bound directly to the promoter region of PIN1a but not of PIN3b. Transient expression assays confirmed that LPA1 and KLP transcriptionally activate PIN1a, and that coexpression of KLP and LPA1 had an additive effect on the activation of PIN1a, suggesting that KLP enhances LPA1 transcriptional activation activity.
Taken together, our results show that KLP is a novel LPA1 interactor that promotes resistance of rice to ShB.
纹枯病（ShB）是一种影响水稻生产的毁灭性病害。此前，我们报道过松散株型1（LPA1）可促进对纹枯病的抗性。然而，LPA1赋予这种病害抗性的机制尚未得到广泛研究。值得注意的是，调节LPA - 1活性的相互作用因子仍然未知。
在本研究中，我们通过酵母双杂交、双分子荧光互补（BiFC）和免疫共沉淀（co - IP）分析，确定了水稻细胞细胞核中驱动蛋白样蛋白（KLP）与LPA1之间的相互作用。为了研究KLP在促进对纹枯病抗性中的作用，将野生型、klp突变体和KLP过表达（KLP OX）水稻植株接种立枯丝核菌AG1 - IA。结果表明，与野生型对照相比，klp突变体更易感病，而KLP OX植株对纹枯病的易感性较低。由于LPA1转录激活PIN - FORMED 1a（PIN1a），我们检测了8个相关PIN基因的表达。结果显示，只有PIN1a和PIN3b的表达与KLP表达水平一致。此外，染色质免疫沉淀（ChIP）分析表明，KLP直接结合到PIN1a的启动子区域，而不结合PIN3b的启动子区域。瞬时表达分析证实，LPA1和KLP转录激活PIN1a，并且KLP和LPA1的共表达对PIN1a的激活具有累加效应，表明KLP增强了LPA1的转录激活活性。
综上所述，我们的结果表明KLP是一种新型的LPA1相互作用因子，可促进水稻对纹枯病的抗性。
