The development of insecticidal chemicals (commonly termed pesticides) has revolutionized the process of cultivation in agriculture; yet, similarly to the development of antimicrobial resistance in pathogens, insects can rapidly develop resistance to these chemicals (Alyokhin & Chen, 2017). Pesticides can also negatively affect beneficial insects such as pollinators and natural enemies of herbivorous insects (Bourguet & Guillemaud, 2016). Extensive pesticide use also poses risks to farmers and growers who apply the pesticides, as well as consumers who eat the resulting produce (Del Prado-Lu, 2015; Bourguet & Guillemaud, 2016). Additionally, pesticides are not always cheap, increasing the economic burden on farmers and consumers alike (Bourguet & Guillemaud, 2016). As a result, alternative strategies are needed to control major crop pests whose damage affects yield and crop quality. A key component of integrated pest management (IPM) is the identification of extant crop varieties carrying resistance phenotypes against pest insects (Stenberg, 2017), in particular, the identification of varieties or lines that emit deterrent volatile organic compounds (VOCs), which can stop pest insects at the source by preventing physical contact, oviposition, and feeding on vulnerable crops. However, rather than killing the insects once a plant is infested, or in the early stages of infestation, why not just keep the insects from infesting in the first place? An exciting study by Ghosh et al., published in this issue of New Phytologist (2023, 1259–1274) identifies a variety of eggplant (aubergine/brinjal) (Solanum melongena L., Solanaceae) resistant to the eggplant/brinjal shoot and fruit borer (Lucinodes orbonalis Guenée, Lepidoptera: Pyralidae), which infests both the vegetative and fruit tissues of the plant (Fig. 1).
This eggplant variety, which originates in the eastern Himalaya region, shows nearly complete resistance to infestation by the adult moth of L. orbonalis, with a complete lack of infested fruits and shoots, and very limited presence of moth eggs on the leaves of the plant – the moth's usual oviposition site. The identification of a naturally resistant variety of eggplant is exciting news, as the pest moth is found world-wide and can cause the loss of 45–100% of marketable fruit (Reshma et al., 2019). As a result of this heavy infestation and loss potential, eggplant receives some of the heaviest pesticide burdens of any cultivated species, with plants sprayed up to 20 times per month in some locations (Del Prado-Lu, 2015). The presence of these pesticides affects not only the moths, but also potentially beneficial insects such as pollinators and parasitoid wasps. Eggplant is largely self-pollinated but benefits from pollination for seed set and fruit production (Pess
杀虫剂(通常称为杀虫剂)的开发彻底改变了农业种植过程;然而,与病原体中抗微生物耐药性的发展类似,昆虫可以迅速对这些化学物质产生耐药性(Alyokhin&;Chen,2017)。农药也会对有益昆虫产生负面影响,如传粉昆虫和草食性昆虫的天敌(Bourguet&;Guillemaud,2016)。广泛使用农药也会给使用农药的农民和种植者以及食用由此产生的农产品的消费者带来风险(Del Prado Lu,2015;Bourguet和Guillemaud,2016)。此外,杀虫剂并不总是便宜的,这增加了农民和消费者的经济负担(Bourguet&;Guillemaud,2016)。因此,需要采取替代策略来控制主要作物害虫,因为这些害虫的危害会影响产量和作物质量。害虫综合治理(IPM)的一个关键组成部分是识别具有对害虫抗性表型的现存作物品种(Stenberg,2017),特别是识别释放威慑性挥发性有机化合物(VOCs)的品种或品系,该化合物可以通过防止物理接触、产卵、,以脆弱的作物为食。然而,与其在植物被感染后或在感染的早期阶段杀死昆虫,为什么不从一开始就防止昆虫感染呢?Ghosh等人的一项令人兴奋的研究。,发表在本期《新植物学家》(2023,1259–1274)上的研究鉴定了一种茄子(茄子/茄子)(茄科,茄科)对茄子/茄子芽和果实蛀虫(露西nodes orbenistor Guenée,鳞翅目:梨科)具有抗性,这种蛀虫侵扰植物的营养组织和果实组织(图1),原产于喜马拉雅东部地区,对L.orbaniste成虫的侵扰表现出几乎完全的抵抗力,完全没有被侵扰的果实和枝条,蛾卵在植物叶片上的存在非常有限——蛾通常的产卵场所。一种具有天然抗性的茄子品种的鉴定是一个令人兴奋的消息,因为这种害虫蛾在世界各地都有发现,并可能导致45-100%的可销售水果损失(Reshma et al.,2019)。由于这种严重的虫害和损失潜力,茄子受到的农药负担是所有栽培物种中最重的,在一些地方,植物每月喷洒20次(Del Prado Lu,2015)。这些杀虫剂的存在不仅影响蛾类,还影响潜在的有益昆虫,如传粉昆虫和寄生蜂。茄子在很大程度上是自花授粉的,但从授粉中受益于结实和果实生产(Pessarakli&;Dris,2004)。由于杀虫剂漂移到邻近作物和未开垦的自然区域,传粉昆虫和其他有益昆虫也可能受到大量喷洒的影响。然而,虽然鉴定单一抗性品种是茄子作物IPM向前迈出的关键一步,但了解对蛾类的抗性机制,甚至可能确定保护其他具有类似虫害风险的作物的方法,是下一步的关键。Ghosh等人。在他们的研究中详细阐述了这一点。作者选择了七个茄子品种,包括抗性品系和六个流行的印度栽培品种,并在田间条件下测试了它们对蛾类及其毛虫幼虫产卵和伤害的易感性。这些测试确定品种RC-RL-22(以下简称RL22)是一个异常品种,与六个流行品种相比,产卵非常有限,没有发现损伤。使用固相微萃取(SPME)和气相色谱-质谱联用(GC–MS),作者共鉴定了7个品种中释放的21种叶挥发物,主要是苯类和脂肪酸衍生(FAD)化合物。它们鉴定的挥发物包括常见的化合物,如香叶醇、(Z)-3-己烯-1-醇、苯乙醛和水杨酸甲酯,其中一些已被证明在草食性昆虫的寄主选择中发挥作用(Theis,2006;Knauer和Schiestl,2017)。有趣的是,品种RL22与其他选择的品种具有完全不同的叶片挥发性特征,除了排放其他品种中不存在的常见单萜醇香叶醇外,还显示出苯类化合物的排放减少和FADs水平的高度增加。接下来,作者使用真实植物和人工植物在受控环境中测试了蛾类的偏好。人工植物补充了各自品种叶挥发物的二氯甲烷提取物,以证明叶挥发物排放的作用,而不是纹理或视觉线索在吸引蛾类和产卵中的作用。 回顾现场研究,RL22在两次试验中都不适合雌蛾产卵,表明其产卵水平与不添加挥发物的人工植物相当。在鉴定了RL22中的七种关键挥发物后,作者评估了它们在使用人工植物驱动蛾产卵行为中的个体作用。在这七种挥发物中,只有香叶醇对产卵有影响,严重减少了蛾在人工植物上的产卵。当其他六个(非RL22)易感品种的叶片补充香叶醇时,产卵量再次显著下降,表明单独的香叶醇足以驱动产卵排斥行为。尽管香叶醇先前已被证明是一种天然杀菌剂(Chen et al.,2023)和杀虫剂(Reis et al.,2016),表现出许多其他生物效应(Chen&;Viljoen,2010),但在这种情况下,它的作用更早,可以强烈阻止产卵,防止虫害和损害。在这一阶段对香叶醇的鉴定表明,它可以用于IPM,将其喷洒在田间流行的易感品种的叶片上很可能会减少产卵和损害。然而,作者更进一步,确定了RL22植物中香叶醇排放的遗传基础。利用与已知牵牛属的序列相似性 × 作者在茄子中鉴定了一种推定的香叶醇合酶(SmGS),并在异源系统中表达,证明它足以催化香叶焦磷酸(GPP,常见的单萜类前体)转化为香叶醇。在植物中,通过优雅的靶向特异性病毒诱导的基因沉默(VIGS)证实了SmGS对于RL22产生香叶醇是必要的。使用VIGS植物和野生型对照对雌蛾进行的行为分析表明,通过沉默SmGS,RL22中香叶醇的损失强烈影响了蛾的行为和产卵,与野生型RL22相比,98%的卵产在沉默的植物上。用香叶醇补充沉默的植物至正常的RL22水平恢复了它们的排斥性。SmGS及其在体外和植株中的功能的鉴定不仅为茄子品种的香叶醇合酶功能的遗传筛选铺平了道路,而且为其他作物物种的选择性育种或基因编辑开辟了一条前进的道路,香叶醇可能在阻止昆虫产卵和破坏方面发挥作用。未来,育种家可以简单地筛选叶片挥发性排放物中是否存在香叶醇,并将其作为筛选品种抗性表型的“第一道关”,而不是依靠昂贵而耗时的田间试验来确定茄子的抗性品种。作者没有对SmGS在其他茄子品种中的功能进行测序和确定,这似乎是未来开发和评估抗虫品种的下一步。确定RL22生产香叶醇是否具有脱靶效应也将是一件有趣的事情,例如影响传粉昆虫的造访、天敌的吸引或影响茄子的果实风味。如果没有,这将香叶醇定位为理想的生物威慑害虫蛾类及其幼虫的侵扰。这项工作还应激励未来在鉴定和将天然抗性品种纳入农业方面的工作,并作为如何在田间和受控条件下鉴定负责抗性的植物次生代谢产物及其遗传基础的模板。总之,作者确定了香叶醇,一种在至少31个植物科中发现的常见单萜类化合物(Schiestl,2010),以及一种由所有陆地植物中发现的一种常见前体的一个步骤催化的化合物,作为茄子中一种严重害虫的产卵威慑物。这代表着在茄子和其他重要作物物种的IPM方面迈出了令人兴奋的一步。它为研究常见的植物挥发物如何阻止害虫物种,以及它们在吸引传粉昆虫方面更为人所知的作用打开了新的大门。此外,由于香叶醇通常是传统农药的更安全的替代品,并且可以很容易地通过细菌表达系统在体外生产,因此将香叶醇应用于无抗性品种代表着在农业及其他领域以可持续的方式利用植物天然产物的潜在进步。与依赖具有显著脱靶作用的传统杀虫剂不同,发现了一种对地上部和果部蛀虫具有天然抗性的茄子,以及其抗性的化学和遗传基础,为IPM提供了一条前进的道路。 通过
{"title":"Reducing eggs on eggplant: a common naturally emitted plant volatile could replace insecticides in the ‘king of vegetables’","authors":"Kelsey J. R. P. Byers","doi":"10.1111/nph.19172","DOIUrl":"https://doi.org/10.1111/nph.19172","url":null,"abstract":"<p>The development of insecticidal chemicals (commonly termed pesticides) has revolutionized the process of cultivation in agriculture; yet, similarly to the development of antimicrobial resistance in pathogens, insects can rapidly develop resistance to these chemicals (Alyokhin & Chen, <span>2017</span>). Pesticides can also negatively affect beneficial insects such as pollinators and natural enemies of herbivorous insects (Bourguet & Guillemaud, <span>2016</span>). Extensive pesticide use also poses risks to farmers and growers who apply the pesticides, as well as consumers who eat the resulting produce (Del Prado-Lu, <span>2015</span>; Bourguet & Guillemaud, <span>2016</span>). Additionally, pesticides are not always cheap, increasing the economic burden on farmers and consumers alike (Bourguet & Guillemaud, <span>2016</span>). As a result, alternative strategies are needed to control major crop pests whose damage affects yield and crop quality. A key component of integrated pest management (IPM) is the identification of extant crop varieties carrying resistance phenotypes against pest insects (Stenberg, <span>2017</span>), in particular, the identification of varieties or lines that emit deterrent volatile organic compounds (VOCs), which can stop pest insects at the source by preventing physical contact, oviposition, and feeding on vulnerable crops. However, rather than killing the insects once a plant is infested, or in the early stages of infestation, why not just keep the insects from infesting in the first place? An exciting study by Ghosh <i>et al</i>., published in this issue of <i>New Phytologist</i> (<span>2023</span>, 1259–1274) identifies a variety of eggplant (aubergine/brinjal) (<i>Solanum melongena</i> L., Solanaceae) resistant to the eggplant/brinjal shoot and fruit borer (<i>Lucinodes orbonalis</i> Guenée, Lepidoptera: Pyralidae), which infests both the vegetative and fruit tissues of the plant (Fig. 1).</p><p>This eggplant variety, which originates in the eastern Himalaya region, shows nearly complete resistance to infestation by the adult moth of <i>L. orbonalis</i>, with a complete lack of infested fruits and shoots, and very limited presence of moth eggs on the leaves of the plant – the moth's usual oviposition site. The identification of a naturally resistant variety of eggplant is exciting news, as the pest moth is found world-wide and can cause the loss of 45–100% of marketable fruit (Reshma <i>et al</i>., <span>2019</span>). As a result of this heavy infestation and loss potential, eggplant receives some of the heaviest pesticide burdens of any cultivated species, with plants sprayed up to 20 times per month in some locations (Del Prado-Lu, <span>2015</span>). The presence of these pesticides affects not only the moths, but also potentially beneficial insects such as pollinators and parasitoid wasps. Eggplant is largely self-pollinated but benefits from pollination for seed set and fruit production (Pess","PeriodicalId":48887,"journal":{"name":"New Phytologist","volume":"240 3","pages":"915-917"},"PeriodicalIF":9.4,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/nph.19172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}