Cry1Ab rice does not impact biological characters and functional response of Cyrtorhinus lividipennis preying on Nilaparvata lugens eggs

One concern about the use of transgenic plants is their potential risk to natural enemies. In this study, using the eggs of the rice brown planthopper, Nilaparvata lugens, as a food source, we investigated the effects of Cry1 Ab rice on the biological characteristics and functional response of an important predator Cyrtorhinus lividipennis. The results showed that the survival ability（adult emergence rate and egg hatching rate）, development（egg duration, nymphal developmental duration）, adult fresh weight, adult longevity and fecundity of C. lividipennis on Bt rice plants were not significantly different compared to those on non-Bt rice plants. Furthermore, two important parameters of functional response（instantaneous search rate and handling time） were not significantly affected by Bt rice. In conclusion, the tested Cry1 Ab rice does not adversely impact the biological character and functional response of C. lividipennis.

Diclofop-methyl affects microbial rhizosphere community and induces systemic acquired resistance in rice

Diclofop-methyl（DM）,a widely used herbicide in food crops,may partly contaminate the soil surface of natural ecosystems in agricultural area and exert toxic effects at low dose to nontarget plants.Even though rhizosphere microorganisms strongly interact with root cells,little is known regarding their potential modulating effect on herbicide toxicity in plants.Here we exposed rice seedlings（Xiushui 63） to 100 μg/L DM for 2 to 8 days and studied the effects of DM on rice rhizosphere microorganisms,rice systemic acquired resistance（SAR） and rice-microorganisms interactions.The results of metagenomic 16 S rDNA Illumina tags show that DM increases bacterial biomass and affects their community structure in the rice rhizosphere.After DM treatment,the relative abundance of the bacterium genera Massilia and Anderseniella increased the most relative to the control.In parallel,malate and oxalate exudation by rice roots increased,potentially acting as a carbon source for several rhizosphere bacteria.Transcriptomic analyses suggest that DM induced SAR in rice seedlings through the salicylic acid（but not the jasmonic acid） signal pathway.This response to DM stress conferred resistance to infection by a pathogenic bacterium,but was not influenced by the presence of bacteria in the rhizosphere since SAR transcripts did not change significantly in xenic and axenic plant roots exposed to DM.The present study provides new insights on the response of rice and its associated microorganisms to DM stress.