A Turnip Mosaic Virus Determinant of Systemic Necrosis in Nicotiana benthamiana and a Novel Resistance-Breaking Determinant in Chinese Cabbage Identified from Chimeric Infectious Clones
A Turnip Mosaic Virus Determinant of Systemic Necrosis in Nicotiana benthamiana and a Novel Resistance-Breaking Determinant in Chinese Cabbage Identified from Chimeric Infectious Clones
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DOI：
10.1094/phyto-08-18-0323-r
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发表时间：
2019-09-01
期刊：
影响因子：
3.2
通讯作者：
Lim, Hyoun-Sub
中科院分区：
文献类型：
--
作者：
Kim, Ik-Hyun;Ju, Hye-Kyoung;Lim, Hyoun-Sub
韩国芜菁花叶病毒(TuMV)侵染株系KIH1和HJY1的基因组核苷酸同源性为88.1%，多蛋白氨基酸同源性为96.4%，它们分别引起烟草的系统坏死和轻度花叶病。这些分离物之间的嵌合结构交换了KIH1(K)和HJY1(H)的5‘、中心和3’结构域，其中字母的顺序指示了这些结构域的起源。KIH1和嵌合体KHh和KKH引起全身坏死，而HJY1和嵌合体HHK、HKK和HKH引起轻微症状，表明坏死的决定因素在KIH1的5‘3.9kb以内；所含的P1、辅助成分蛋白水解酶、P3、6K1和柱状包涵体N端区的氨基酸同源性分别为90.06、98.91、93.80、100和100%。从马铃薯X病毒载体中表达的P1或P3只在KIH1和HJY1的P3之间产生了症状差异，这表明P3在本氏新月藻的坏死中起到了作用。嵌合体KKH感染白菜。北京人‘Norang’对KIH1和HJY1都有抗性，表明需要两个独立的TuMV决定簇来克服这种抗性。不同的TuMV分离物、嵌合体和重组体克服育种系抗性的能力可能使鉴定新的抗性基因成为可能。
Infectious clones of Korean turnip mosaic virus (TuMV) isolates KIH1 and HJY1 share 88.1% genomic nucleotides and 96.4% polyprotein amino acid identity, and they induce systemic necrosis or mild mosaic, respectively, in Nicotiana benthamiana. Chimeric constructs between these isolates exchanged the 5', central, and 3' domains of KIH1 (K) and HJY1 (H), where the order of the letters indicates the origin of these domains. KIH1 and chimeras KHH and KKH induced systemic necrosis, whereas HJY1 and chimeras HHK, HKK, and HKH induced mild symptoms, indicating the determinant of necrosis to be within the 5' 3.9 kb of KIH1; amino acid identities of the included P1, Helper component protease, P3, 6K1, and cylindrical inclusion N-terminal domain were 90.06, 98.91, 93.80, 100, and 100%, respectively. Expression of P1 or P3 from a potato virus X vector yielded symptom differences only between P3 of KIH1 and HJY1, implicating a role for P3 in necrosis in N. benthamiana. Chimera KKH infected Brassica rapa var. pekinensis 'Norang', which was resistant to both KIH1 and HJY1, indicating that two separate TuMV determinants are required to overcome the resistance. Ability of diverse TuMV isolates, chimeras, and recombinants to overcome resistance in breeding lines may allow identification of novel resistance genes.