玉米條紋病毒導(dǎo)致了全世界經(jīng)濟損失最嚴重的作物疾病之一
非洲科學(xué)家發(fā)現(xiàn)了全世界經(jīng)濟損失最嚴重的作物疾病之一是如何出現(xiàn)的，他們希望利用這些信息培育抗病的轉(zhuǎn)基因作物,。
科學(xué)家比較了非洲大陸各地毒力很強的玉米條紋病毒（MSV）和毒力稍弱的這種病毒的遺傳序列,，該病毒可以感染其他草本糧食作物，例如小麥和燕麥,。
來自南非開普敦大學(xué)的科學(xué)家Arvind Varsani說：“我們發(fā)現(xiàn)兩種相對溫和的草病毒通過遺傳重組而合并,。”
這種合并導(dǎo)致了比它的祖先毒力更強的古代MSV病毒，在它迅速傳遍非洲大陸之前就具有了感染玉米的能力,。
這組科學(xué)家認為這發(fā)生在大約一個世紀之前,，就在商業(yè)農(nóng)業(yè)取代生存農(nóng)業(yè)、而玉米開始取代非洲本土作物的時候,。
這項發(fā)現(xiàn)發(fā)表在了《普通病毒學(xué)雜志》9月號（Journal of General Virology）上,，它凸顯了研究植物疾病的重要性。
Varsani告訴本網(wǎng)站說：“我們的研究成果意味著DNA病毒比此前認為的進化速度更快,。這種快速突變增加了新的植物病毒出現(xiàn)的可能性,。”
南非傳染病和分子醫(yī)學(xué)研究所的Darren Martin領(lǐng)導(dǎo)了這項研究,，他說：“盡管植物疾病并沒有得到公眾太多的關(guān)注，它們對糧食生產(chǎn)的影響導(dǎo)致的發(fā)展中國家的苦難比許多著名的人類疾病更多,。”
研究植物疾病可以提供關(guān)于病原體的信息,，后者可以用于培育抗病作物。今年早些時候,，開普敦大學(xué)的研究組分析了至少200份被感染玉米的樣本,。本月將開始對來自布基納法索、中非共和國,、科特迪瓦,、納米比亞和津巴布韋的樣本進行分析，結(jié)果將存入一個數(shù)據(jù)庫,。
開普敦大學(xué)分子和細胞生物學(xué)系的Dionne Shepherd正在負責(zé)培育能夠抵抗這種條紋病毒的轉(zhuǎn)基因玉米,。
Shepherd告訴本網(wǎng)站說：“我們已經(jīng)培育出了抗條紋病毒的玉米。如今我們需要證明它可以在整個撒哈拉以南非洲地區(qū)的不同環(huán)境下生長,。”（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of General Virology Published online ahead of print on 27 June 2008 as DOI 10.1099/vir.0.2008/003590-0
Recombination,decreased host specificity and increased mobility may have driven the emergence of maize streak virus as an agricultural pathogen
Arvind Varsani,Dionne N.Shepherd,Adérito L.Monjane,Betty E.Owor,Julia B.Erdmann,Edward P.Rybicki,Michel Peterschmitt,Rob W.Briddon,Peter G.Markham,Sunday Oluwafemi,Oliver P.Windram,Pierre Lefeuvre,Jean-Michel Lettand Darren P.Martin
Maize streak virus(MSV;family Geminiviridae,genus Mastrevirus),the causal agent of maize streak disease,ranks amongst the most serious biological threats to food security in subSaharan Africa.Although five distinct MSV strains have been currently described,only one of these–MSV-A–causes severe disease in maize.Due primarily to their not being an obvious threat to agriculture,very little is known about the‘grass-adapted’MSV strains,MSV-B,-C,-D and-E.Since comparing the genetic diversities,geographical distributions and natural host ranges of MSV-A with the other MSV strains could provide valuable information on the epidemiology,evolution and emergence of MSV-A,we carried out a phylogeographical analysis of MSVs found in uncultivated indigenous African grasses.Amongst the 83 new MSV genomes presented here,we report the discovery of six new MSV strains(MSV-F to -K).The non-random recombination breakpoint distributions detectable with these and other available mastrevirus sequences partially mirror those seen in begomoviruses,implying that the forces shaping these breakpoint patterns have been largely conserved since the earliest geminivirus ancestors.We present evidence that the ancestor of all MSV-A variants was the recombinant progeny of ancestral MSV-B and MSV-G/-F variants.While it remains unknown whether recombination influenced the emergence of MSV-A in maize,our discovery that MSV-A variants may both move between and become established in different regions of Africa with greater ease,and infect more grass species than other MSV strains,goes some way towards explaining why MSV-A is such a successful maize pathogen.
