Chen Gong, Su Qi, Shi Xiaobin, Liu Xin, Peng Zhengke, Zheng Huixin, Xie Wen, Xu Baoyun, Wang Shaoli, Wu Qingjun, Zhou Xuguo, Zhang Youjun
College of Plant Protection, Hunan Agricultural UniversityChangsha, China; Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China.
Institute of Insect Sciences, College of Agriculture, Yangtze University Jingzhou, China.
Front Physiol. 2017 Mar 16;8:146. doi: 10.3389/fphys.2017.00146. eCollection 2017.
Although, insect herbivores are generally thought to select hosts that favor the fitness of their progeny, this "mother-knows-best" hypothesis may be challenged by the presence of a plant virus. Our previous study showed that the whitefly, , the obligate vector for transmitting (TYLCV), preferred to settle and oviposit on TYLCV-infected rather than healthy host plant, . The performances of larvae and adults were indeed improved on virus-infected , which is consistent with "mother-knows-best" hypothesis. In this study, Q displayed the same preference to settle and oviposit on (TSWV)-infected host plants, and , respectively. As a non-vector of TSWV, however, insect performance was impaired since adult body size, longevity, survival, and fecundity were reduced in TSWV infected . This appears to be an odor-mediated behavior, as plant volatile profiles are modified by viral infection. Infected plants have reduced quantities of o-xylene and α-pinene, and increased levels of phenol and 2-ethyl-1-hexanol in their headspace. Subsequent behavior experiments showed that o-xylene and α-pinene are repellant, while phenol and 2-ethyl-1-hexanol are attractive. This indicates that the preference of for virus-infected plants is modulated by the dynamic changes in the volatile profiles rather than the subsequent performances on virus-infected plants.
虽然一般认为植食性昆虫会选择有利于其后代适合度的寄主，但这种“母亲最清楚”的假说可能会受到植物病毒存在的挑战。我们之前的研究表明，粉虱，即传播番茄黄化曲叶病毒（TYLCV）的专性介体，更喜欢在感染TYLCV的而非健康的寄主植物上栖息和产卵。在感染病毒的寄主植物上，粉虱幼虫和成虫的表现确实有所改善，这与“母亲最清楚”假说相符。在本研究中，西花蓟马分别对感染番茄斑萎病毒（TSWV）的寄主植物烟草和番茄表现出相同的栖息和产卵偏好。然而，作为TSWV的非介体，由于在感染TSWV的寄主植物上成虫体型、寿命、存活率和繁殖力降低，昆虫的表现受到损害。这似乎是一种由气味介导的行为，因为病毒感染会改变植物挥发物谱。感染病毒的植物在其顶空中邻二甲苯和α-蒎烯的含量减少，苯酚和2-乙基-1-己醇的含量增加。随后的行为实验表明，邻二甲苯和α-蒎烯具有驱避作用，而苯酚和2-乙基-1-己醇具有吸引作用。这表明西花蓟马对感染病毒植物的偏好是由挥发物谱的动态变化而非在感染病毒植物上的后续表现所调节的。
