Isolation and evaluation of the biocontrol potential of Talaromyces spp. against rice sheath blight guided by soil microbiome

Rice sheath blight caused by Rhizoctonia solani is the major disease of rice that seriously threatens food security worldwide. Efficient and eco-friendly biological approaches are urgently needed since no resistant cultivars are available. In this study, fallow and paddy soils were initially subjected to microbiome analyses, and the results showed that Talaromyces spp. were significantly more abundant in the paddy soil, while Trichoderma spp. were more abundant in the fallow soil, suggesting that Talaromyces spp. could live and survive better in the paddy soil. Five Talaromyces isolates, namely, TF-04, TF-03, TF-02, TF-01 and TA-02, were isolated from the paddy soil using sclerotia of R. solani as baits and were further evaluated for their activity against rice sheath blight. These isolates efficiently parasitized the hyphae and rotted the sclerotia even at higher water contents in the sterilized sand and the soil. Isolate TF-04 significantly promoted rice growth, reduced the severity of rice sheath blight and increased the rice yield under outdoor conditions. Defence-related genes were upregulated and enzyme activities were enhanced in rice treated with isolate TF-04. Our research supplies a microbiome-guided approach to screen biological control agents and provides Talaromyces isolates to biologically control rice sheath blight.

Absolute Quantitation of Plant Proteins

Among targeted proteomic techniques, AQUA-MRM is considered as one of the most reliable for accurate protein quantitation. This method displays high sensitivity, specificity, and reproducibility compared to many common biochemical techniques by coupling the use of unique, heavy-labeled peptide standards and triple-quadrupole mass spectrometry. However, there are several important steps that are required for successful development and validation of a robust AQUA-MRM assay. The following protocol outlines and details the key steps necessary for plant sample preparation as well as AQUA-MRM development and validation, specifically for absolute quantitation of plant proteins in vivo. © 2018 by John Wiley & Sons, Inc.