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

2021 ◽  
Vol 12 ◽  
Author(s):  
Long Wang ◽  
Xiaohui Wang ◽  
Fanqi Gao ◽  
Changning Lv ◽  
Likun Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Expression ◽  
Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Maize Yield ◽  
Elevated Carbon Dioxide ◽  
Mythimna Separata ◽  
Bt Toxin ◽  
Maize Leaves ◽  
Growth Development

The promotion and application of transgenic Bt crops provides an approach for the prevention and control of target lepidopteran pests and effectively relieves the environmental pressure caused by the massive usage of chemical pesticides in fields. However, studies have shown that Bt crops will face a new risk due to a decrease in exogenous toxin content under elevated carbon dioxide (CO2) concentration, thus negatively affecting the ecological sustainability of Bt crops. Arbuscular mycorrhizal fungi (AMF) are important beneficial microorganisms that can effectively improve the nutrient status of host plants and are expected to relieve the ecological risk of Bt crops under increasing CO2 due to global climate change. In this study, the Bt maize and its parental line of non-transgenic Bt maize were selected and inoculated with a species of AMF (Funneliformis caledonium, synonyms: Glomus caledonium), in order to study the secondary defensive chemicals and yield of maize, and to explore the effects of F. caledonium inoculation on the growth, development, and reproduction of the pest Mythimna separata fed on Bt maize and non-Bt maize under ambient carbon dioxide concentration (aCO2) and elevated carbon dioxide concentration (eCO2). The results showed that eCO2 increased the AM fungal colonization, maize yield, and foliar contents of jasmonic acid (JA) and salicylic acid (SA), but decreased foliar Bt toxin content and Bt gene expression in Bt maize leaves. F. caledonium inoculation increased maize yield, 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, F. 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 indicated that F. 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. Therefore, this study confirms that the AMF can increase the yield and promote the expression levels of its endogenous (JA, SA) and exogenous (Bt toxin) secondary defense substances of Bt maize under eCO2, and finally can enhance the insect resistance capacity of Bt crops, which will help ensure the sustainable utilization and safety of Bt crops under climate change.

scholarly journals Space-based geoengineering: Challenges and requirements

2009 ◽  
Vol 224 (3) ◽  
pp. 571-580 ◽  
Author(s):  
C R McInnes
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Large Scale ◽  
Climate Model ◽  
Carbon Dioxide Concentration ◽  
Complex Solution ◽  
Lagrange Point ◽  
Simple Climate Model ◽  
Earth’S Climate

The prospect of engineering the Earth's climate (geoengineering) raises a multitude of issues associated with climatology, engineering on macroscopic scales, and indeed the ethics of such ventures. Depending on personal views, such large-scale engineering is either an obvious necessity for the deep future, or yet another example of human conceit. In this article a simple climate model will be used to estimate requirements for engineering the Earth's climate, principally using space-based geoengineering. Active cooling of the climate to mitigate anthropogenic climate change due to a doubling of the carbon dioxide concentration in the Earth's atmosphere is considered. This representative scenario will allow the scale of the engineering challenge to be determined. It will be argued that simple occulting discs at the interior Lagrange point may represent a less complex solution than concepts for highly engineered refracting discs proposed recently. While engineering on macroscopic scales can appear formidable, emerging capabilities may allow such ventures to be seriously considered in the long term. This article is not an exhaustive review of geoengineering, but aims to provide a foretaste of the future opportunities, challenges, and requirements for space-based geoengineering ventures.

NITROUS OXIDE AND CARBON DIOXIDE EMISSION FROM MAIZE (Zea maysL.) UNDER FERTILISER APPLICATION AND ELEVATED CARBON DIOXIDE IN NORTHWEST INDIA

2014 ◽  
Vol 50 (4) ◽  
pp. 625-643
Author(s):  
A. DARIPA ◽  
A. BHATIA ◽  
R. TOMER ◽  
S. D. SINGH ◽  
N. JAIN ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Agricultural Research ◽  
Indian Agricultural Research Institute ◽  
Carbon Dioxide Emission ◽  
Maize Yield ◽  
Elevated Carbon Dioxide ◽  
Carbon Efficiency ◽  
Fertiliser Application ◽  
Northwest India

SUMMARYA field experiment was carried out at the farm of Indian Agricultural Research Institute, New Delhi to quantify the effect of elevated carbon dioxide (CO2) and different levels of N fertiliser application on nitrous oxide (N2O) and carbon dioxide (CO2) emissions from soil under maize. The experiment included five treatments: 60 kg N ha−1under ambient CO2(385 ppm) in open plots, 120 kg N ha−1under ambient CO2(385 ppm) in open plots, 160 kg N ha−1under ambient CO2(385 ppm) in open plots, 120 kg N ha−1under ambient CO2(385 ppm) in open top chambers (OTC) and 120 kg N ha−1under elevated CO2(500 ± 50 ppm) in the OTC. Peaks of N2O flux were observed after every dose of N application. Cumulative N2O emission was 13% lower under ambient CO2as compared to the elevated CO2concentrations. There was an increase in CO2emissions with application of N from 60 kg ha−1to 160 kg ha−1. Higher yield and root biomass was observed under higher N treatment (160 kg N ha−1). There was no significant increase in maize yield under elevated CO2as compared to ambient CO2. The carbon emitted was more than the carbon fixed under elevated CO2as compared to ambient CO2levels. The carbon efficiency ratio (C fixed/C emitted) was highest in ambient CO2treatment in the OTC.

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