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2016年5月11日/生物谷BIOON/–今天，Nature Biotechnology期刊同时发表三篇关于作物抗病性的重要论文。它们报道分离出新的抗病基因，并且成功地将抗病基因转移到小麦、大豆和马铃薯中。双刀片基金会（2Blades Foundation）资助了这些研究。
双刀片基金会通过针对性地控制作物疾病来解决对全世界农业生产不断增加的需求。据估计，植物病原体导致全球作物损失大约15%，而且一些病原体甚至能够导致全部作物绝收。尽管使用农业化学药品和抗病性作物品种能够控制作物疾病，但是病原体群体快速适应这些措施。植物科学近期的发现为针对病原体开发出更加持久的遗传抗性提供机会，然而，在过去20年，很少将这些发现在田间加以应用和推广。
这三篇论文着重关注小麦秆锈病（wheat stem rust, WSR）、亚洲大豆锈菌病（Asian soybean rust, ASR）和马铃薯晚疫病（potato late blight, PLB）。这三种由植物病原体感染导致的疾病很难控制，而且每种疾病能够导致产量损失80%以上。
（1）小麦提供20%的全球消费的卡路里和蛋白。小麦秆锈病（WSR）影响小麦产量。WSR抗性小麦品种在上个世纪五十和六十年代被培育出和广泛地使用，但是新兴的小麦秆锈病菌菌株能够克服这些小麦品种的抗病性。在第一项新的研究中，来自英国约翰伊恩斯中心（John Innes Centre）和澳大利亚联邦科学与工业研究组织（CSIRO）的研究人员详细描述了在被称作MutRenSeq（Mutational Resistance Gene Enrichment Sequencing, 突变抗病基因富集测试）的抗病基因鉴定方法上的一项关键的发现：利用这种方法分离出两种抗病基因Sr22和Sr45。相关研究结果于2016年4月25日在线发表在Nature Biotechnology期刊上，论文标题为“Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture”。
（2）大豆是一种至关重要的蛋白和食用油来源，全球产量超过3亿多吨。亚洲大豆锈菌病（ASR）导致大豆产量损失高达80%，并且威胁着南美洲的大豆生产，其中世界上一半以上的大豆在南美洲种植。持久的遗传抗性一直缺乏，而且仅在巴西，化学控制措施每年花费200万以上美元。在第二项新的研究中，来自英国诺维奇科技园塞恩斯伯里实验室（Sainsbury Laboratory）、巴西维索萨联邦大学（Universidade Federal de Viçosa）和美国加州大学戴维斯分校、杜邦先锋良种公司的研究人员从木豆（Cajanus cajan）中分离出基因CcRpp1，将它导入大豆中，并且首次证实商业大豆产生高水平的ASR抵抗力。这种转基因疾病防治策略的进一步开展旨在持久地提供稳定的产量，同时降低对化学处理的需求。相关研究结果于2016年4月25日在线发表在Nature Biotechnology期刊上，论文标题为“A pigeonpea gene confers resistance to Asian soybean rust in soybean”。
（3）众所周知，在十九世纪四十年代晚期，马铃薯晚疫病（PLB）破坏爱尔兰马铃薯作物，从而导致大范围的饥荒。PLB易感性仍然是大多数商业马铃薯品种的一大威胁。在第三项新的研究中，来自英国诺维奇科技园塞恩斯伯里实验室和诺维奇科技园基因组分析中心的研究人员从光果龙葵（Solanum americanum）—马铃薯的一种野生近缘种—中分离出一种新的PLB抗性疾病Rpi-amr3，将它导入PLB易感性的马铃薯品种中。相关研究结果于2016年4月25日在线发表在Nature Biotechnology期刊上，论文标题为“Accelerated cloning of a potato late blight–resistance gene using RenSeq and SMRT sequencing”。
作物通常能够自我抵抗疾病，但是植物病原体也能够通过逃避识别克服作物的防御机制。科学家们所要做的是恢复作物“看见”这些病原体的能力。这三项研究取得重大的进步，研究人员将继续开展必要的研究来抵抗作物疾病。（生物谷 Bioon.com）
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Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture
doi:10.1038/nbt.3543
Burkhard Steuernagel, Sambasivam K Periyannan, Inmaculada Hernández-Pinzón, Kamil Witek, Matthew N Rouse, Guotai Yu, Asyraf Hatta, Mick Ayliffe, Harbans Bariana, Jonathan D G Jones, Evans S Lagudah & Brande B H Wulff
Wild relatives of domesticated crop species harbor multiple, diverse, disease resistance (R) genes that could be used to engineer sustainable disease control. However, breeding R genes into crop lines often requires long breeding timelines of 5–15 years to break linkage between R genes and deleterious alleles (linkage drag). Further, when R genes are bred one at a time into crop lines, the protection that they confer is often overcome within a few seasons by pathogen evolution1. If several cloned R genes were available, it would be possible to pyramid R genes2 in a crop, which might provide more durable resistance1. We describe a three-step method (MutRenSeq)-that combines chemical mutagenesis with exome capture and sequencing for rapid R gene cloning. We applied MutRenSeq to clone stem rust resistance genes Sr22 and Sr45 from hexaploid bread wheat. MutRenSeq can be applied to other commercially relevant crops and their relatives, including, for example, pea, bean, barley, oat, rye, rice and maize.
A pigeonpea gene confers resistance to Asian soybean rust in soybean
doi:10.1038/nbt.3554
Cintia G Kawashima, Gustavo Augusto Guimarães, Sônia Regina Nogueira, Dan MacLean, Doug R Cook, Burkhard Steuernagel, Jongmin Baek, Costas Bouyioukos, Bernardo do V A Melo, Gustavo Tristão, Jamile Camargos de Oliveira, Gilda Rauscher, Shipra Mittal, Lisa Panichelli, Karen Bacot, Ebony Johnson, Geeta Iyer, Girma Tabor, Brande B H Wulff, Eric Ward, Gregory J Rairdan, Karen E Broglie, Gusui Wu, H Peter van Esse, Jonathan D G Jones & Sérgio H Brommonschenkel
Asian soybean rust (ASR), caused by the fungus Phakopsora pachyrhizi, is one of the most economically important crop diseases, but is only treatable with fungicides, which are becoming less effective owing to the emergence of fungicide resistance. There are no commercial soybean cultivars with durable resistance to P. pachyrhizi, and although soybean resistance loci have been mapped, no resistance genes have been cloned. We report the cloning of a P. pachyrhizi resistance gene CcRpp1 (Cajanus cajan Resistance against Phakopsora pachyrhizi 1) from pigeonpea (Cajanus cajan) and show that CcRpp1 confers full resistance to P. pachyrhizi in soybean. Our findings show that legume species related to soybean such as pigeonpea, cowpea, common bean and others could provide a valuable and diverse pool of resistance traits for crop improvement.
Accelerated cloning of a potato late blight–resistance gene using RenSeq and SMRT sequencing
doi:10.1038/nbt.3540
Kamil Witek, Florian Jupe, Agnieszka I Witek, David Baker, Matthew D Clark & Jonathan D G Jones
Global yields of potato and tomato crops have fallen owing to potato late blight disease, which is caused by Phytophthora infestans. Although most commercial potato varieties are susceptible to blight, many wild potato relatives show variation for resistance and are therefore a potential source of Resistance to P. infestans (Rpi) genes. Resistance breeding has exploited Rpi genes from closely related tuber-bearing potato relatives, but is laborious and slow1, 2, 3. Here we report that the wild, diploid non-tuber-bearing Solanum americanum harbors multiple Rpi genes. We combine resistance (R) gene sequence capture (RenSeq)4 with single-molecule real-time (SMRT) sequencing (SMRT RenSeq) to clone Rpi-amr3i. This technology should enable de novo assembly of complete nucleotide-binding, leucine-rich repeat receptor (NLR) genes, their regulatory elements and complex multi-NLR loci from uncharacterized germplasm. SMRT RenSeq can be applied to rapidly clone multiple R genes for engineering pathogen-resistant crops.