Jiao Min, Yu Dan, Tan Chenglong, Guo Jia, Lan Dingyun, Han Ershang, Qi Tuo, Voegele Ralf Thomas, Kang Zhensheng, Guo Jun
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
Environ Microbiol. 2017 Oct;19(10):4177-4189. doi: 10.1111/1462-2920.13881. Epub 2017 Sep 14.
Calcium/calmodulin-dependent kinases (CaMKs) are Ser/Thr protein kinases (PKs) that respond to changes in cytosolic free Ca and play diverse roles in eukaryotes. In fungi, CAMKs are generally classified into four families CAMK1, CAMKL, RAD53 and CAMK-Unique. Among these, CAMKL constitutes the largest family. In some fungal plant pathogens, members of the CaMKL family have been shown to be responsible for pathogenesis. However, little is known about their role(s) in rust fungi. In this study, we functionally characterized a novel PK gene, PsCaMKL1, from Puccinia striiformis f. sp. tritici (Pst). PsCaMKL1 belongs to a group of PKs that is evolutionarily specific to basidiomyceteous fungi. PsCaMKL1 shows little intra-species polymorphism between Pst isolates. PsCaMKL1 transcripts are highly elevated at early infection stages, whereas gene expression is downregulated in barely germinated urediospores under KN93 treatment. Overexpression of PsCaMKL1 in fission yeast increased resistance to environmental stresses. Knock down of PsCaMKL1 using host-induced gene silencing (HIGS) reduced the virulence of Pst accompanied by reactive oxygen species (ROS) accumulation and a hypersensitive response. These results suggest that PsCaMKL1 is a novel pathogenicity factor that exerts it virulence function by regulating ROS production in wheat.
钙/钙调蛋白依赖性激酶（CaMKs）是丝氨酸/苏氨酸蛋白激酶（PKs），可响应胞质游离钙的变化，并在真核生物中发挥多种作用。在真菌中，钙调蛋白依赖性激酶通常分为四个家族：CAMK1、CAMKL、RAD53和CAMK-独特家族。其中，CAMKL构成最大的家族。在一些真菌植物病原体中，CaMKL家族成员已被证明与发病机制有关。然而，它们在锈菌中的作用却知之甚少。在本研究中，我们对来自小麦条锈菌（Pst）的一个新的蛋白激酶基因PsCaMKL1进行了功能鉴定。PsCaMKL1属于一类在担子菌真菌中具有进化特异性的蛋白激酶。PsCaMKL1在小麦条锈菌分离株之间几乎没有种内多态性。PsCaMKL1转录本在感染早期高度升高，而在KN93处理下几乎未萌发的夏孢子中基因表达下调。在裂殖酵母中过表达PsCaMKL1可增强对环境胁迫的抗性。利用寄主诱导的基因沉默（HIGS）敲低PsCaMKL1可降低小麦条锈菌的毒力，并伴有活性氧（ROS）积累和超敏反应。这些结果表明，PsCaMKL1是一种新的致病因子，通过调节小麦中的ROS产生来发挥其毒力功能。
