Konečná Eva, Šafářová Dana, Navrátil Milan, Hanáček Pavel, Coyne Clarice, Flavell Andrew, Vishnyakova Margarita, Ambrose Mike, Redden Robert, Smýkal Petr
Department of Plant Biology, Mendel University in Brno, Brno, Czech Republic; CEITEC MENDELU, Mendel University in Brno, Brno, Czech Republic.
Department of Cell Biology and Genetics, Palacky University in Olomouc, Olomouc, Czech Republic.
PLoS One. 2014 Mar 7;9(3):e90394. doi: 10.1371/journal.pone.0090394. eCollection 2014.
The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the eIF4E gene to identify novel genetic diversity.
METHODOLOGY/PRINCIPAL FINDINGS: Germplasm of 2803 pea accessions was screened for eIF4E intron 3 length polymorphism, resulting in the detection of four eIF4E(A-B-C-S) variants, whose distribution was geographically structured. The eIF4E(A) variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, eIF4E(B), was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The eIF4E(C) variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The eIF4E(S) variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (eIF4E(A-1-2-3-4-5-6-7), eIF4E(B-1), eIF4E(C-2)) conferred resistance to the P1 PSbMV pathotype.
CONCLUSIONS/SIGNIFICANCE: This work identified novel eIF4E alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible eIF4E(S1) allele. Despite high variation present in wild Pisum accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the pea host.
真核生物翻译起始因子4E已被证明参与植物对包括豌豆在内的多种马铃薯Y病毒的抗性。我们将对豌豆种质多样性的了解与eIF4E基因的知识相结合，以识别新的遗传多样性。
方法/主要发现：对2803份豌豆种质进行了eIF4E内含子3长度多态性筛选，检测到四种eIF4E（A - B - C - S）变体，其分布具有地理结构。赋予对P1 PSbMV致病型抗性的eIF4E（A）变体在53份种质（1.9%）中被发现，其中15份是来自印度、阿富汗、尼泊尔的地方品种，7份来自埃塞俄比亚。一个新发现的变体eIF4E（B）存在于来自埃塞俄比亚（29%）、阿富汗（23%）、印度（20%）、以色列（25%）和中国（39%）的328份种质（11.7%）中。eIF4E（C）变体在来自印度（20%）、阿富汗（33%）、伊比利亚半岛（22%）和巴尔干半岛（9.3%）的91份种质（占总数的3.2%）中被检测到。易感性的eIF4E（S）变体作为野生型占主导。对73个样本进行测序，分别在整个基因中鉴定出34个等位基因，在cDNA中鉴定出26个，在蛋白质变体中鉴定出19个。对15个等位基因进行了病毒学测试，9个等位基因（eIF4E（A - 1 - 2 - 3 - 4 - 5 - 6 - 7）、eIF4E（B - 1）、eIF4E（C - 2））赋予对P1 PSbMV致病型的抗性。
结论/意义：这项工作在具有地理结构的豌豆种质中鉴定出了新的eIF4E等位基因，并表明它们与易感的eIF4E（S1）等位基因独立进化。尽管野生豌豆种质存在高度变异，但它们都不具有抗性等位基因，这支持了野生与作物物种抗性进化模式不同的假设。中亚高地、印度次大陆北部地区、东非和中国被确定为与病原体多样性相对应的豌豆多样性重要中心。本研究中鉴定出的一系列等位基因为研究马铃薯Y病毒与豌豆宿主的共同进化提供了基础。
