What do we know about biological nitrogen fixation in insects? Evidence and implications for the insect and the ecosystem  

作　　者：Nitsan Bar-Shmuel Adi Behar Michal Segoli 

机构地区：[1]Mitrani Department of Desert Ecology,Jacob Blaustein Institutes for Desert Research,Ben-Gurion University of the Negev,Sede Boqer Campus,Israel [2]Kimron Veterinary Institute,Department of Parasitology,Bet Dagan,Israel

出　　处：《Insect Science》2020年第3期392-403,共12页昆虫科学（英文版）

基　　金：We thank Tamir Rosenberg for technical support.We thank Shimon Rachmilevitch,Martin Kaltenpoth,and Itamar Gilady for discussions and comments on earlier versions of the manuscript.We thank the Daniel E.Koshland Fund,the Sol Leshin Program for BGU-UCLA Academic Cooperation,and the Israel Science Foundation(Award No.364/16)for supporting this work.This is publication number 1032 of the Mitrani Department of Desert Ecology。

摘　　要：Many insects feed on a low‐nitrogen diet,and the origin of their nitrogen supply is poorly understood.It has been hypothesized that some insects rely on nitrogen‐fixing bacteria(diazotrophs)to supplement their diets.Nitrogen fixation by diazotrophs has been extensively studied and convincingly demonstrated in termites,while evidence for the occurrence and role of nitrogen fixation in the diet of other insects is less conclusive.Here,we summarize the methods to detect nitrogen fixation in insects and review the available evidence for its occurrence(focusing on insects other than termites).We distinguish between three aspects of nitrogen fixation investigations:(i)detecting the presence of potential diazotrophs;(ii)detecting the activity of the nitrogen‐fixing enzyme;and(iii)detecting the assimilation of fixed nitrogen into the insect tissues.We show that although evidence from investigations of the first aspect reveals ample opportunities for interactions with potential diazotrophs in a variety of insects,demonstrations of actual biological nitrogen fixation and the assimilation of fixed nitrogen are restricted to very few insect groups,including wood‐feeding beetles,fruit flies,leafcutter ants,and a wood wasp.We then discuss potential implications for the insect's fitness and for the ecosystem as a whole.We suggest that combining these multiple approaches is crucial for the study of nitrogen fixation in insects,and argue that further demonstrations are desperately needed in order to determine the relative importance of diazotrophs for insect diet and fitness,as well as to evaluate their overall impact on the ecosystem.

关 键 词：biological nitrogen fixation DIAZOTROPHS gut microbiome insect diet 

分 类 号：Q96[生物学—昆虫学]