AUTHOR=Wang Long , Wang Xiaohui , Gao Fanqi , Lv Changning , Li Likun , Han Tong , Chen Fajun 

TITLE=AMF Inoculation Can Enhance Yield of Transgenic Bt Maize and Its Control Efficiency Against Mythimna separata Especially Under Elevated CO2

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.655060

DOI=10.3389/fpls.2021.655060

ISSN=1664-462X

ABSTRACT=The promotion and application of transgenic Bt crops (Bt crops) provides a new approach for the
prevention and control of target lepidopteran pests, and effectively relieves the environmental
pressure resulted by the massive usage of chemical pesticides in fields. However, studies have
showed that Bt crops will face a new ecological risk of the general decrease in exogenous toxin
content grown under elevated carbon dioxide concentration (eCO2), thus negatively affecting the
ecological sustainability of Bt crops. Arbuscular mycorrhizal fungi (AMF) are important
beneficial microorganism that can effectively improve the nutrient status of host plants, and is
expected to relieve the ecological risk of Bt crops especially under global climate change. In this
study, the Bt maize (serial number: IE09S034, exogenous gene: Cry1Ie) and its parental line of
non-transgenic Bt maize were selected and inoculated with a species of AMF (Glomus
caledonium), in order to study the maize secondary defensive chemicals and maize yields,
simultaneously to explore the indirect effects of G. caledonium inoculation on the growth,
development and reproduction of Mythimna separata fed on Bt mazie and non-Bt maize under
aCO2 and eCO2. The results indicated that eCO2 increased the AMF colonization, maize yields
and the foliar contents of jasmonic acid (JA) and salicylic acid (SA), but decreased foliar Bt
toxin content and Bt gene expression in Bt mazie leaves. G. caledonium inoculation increased
maize yields, foliar JA, SA contents, Bt toxin contents and Bt gene expression in Bt maize leaves,
and positively improved the growth, development, reproduction and food utilization of the M.
separata fed on non-Bt maize. However, G. caledonium inoculation was unfavorable for the
fitness of M. separata fed on Bt maize, and the effect was intensified when combined with eCO2.
It is presumed that G. caledonium inoculation had adverse effects on the production of non-Bt
maize due to the high potential risk of population occurrence of M. separata, while it was just
the opposite for Bt maize. Hence, G. caledonium inoculation was conducive to improving the
performance of Bt maize for the M. separata control, combined with the better insect resistance
under eCO2.