Effect of Radio Frequency Combined with Hot Air Heating on Degradation of Aflatoxin B1 and Corn Quality

This study analyzed the effects of radio frequency-hot air treatment under different conditions of initial corn moisture content (19.05%, 22.25%, and 25.55%), radio frequency heating temperature (55, 65, 75, and 85 ℃) and heating time (10, 15, 20, and 25 min) on the degradation of aflatoxin B1 (AFB1) and corn quality. The results showed that radio frequency-hot air treatment could effectively degrade AFB1. For corn with high initial water content, at the same heating temperature and time, higher initial moisture content resulted in higher residual amount of AFB1. At the same initial water content, the residual amount of AFB1 decreased with the increase in heating temperature and time. Heating time had a greater effect on AFB1 degradation than temperature. Radio frequency-hot air treatment affected corn quality. With increasing heating temperature and time, neither protein nor fat contents significantly changed compared with the control group (P > 0.05), while viscosity significantly decreased (P < 0.05). Low-field nuclear magnetic resonance (NMR) analysis showed marked changes in water mobility during radio frequency heating, and water mobility characteristics were significantly correlated with the gelatinization characteristics, protein, and fat contents of corn (P < 0.05)

SORTING NEXIN2 proteins mediate stomatal movement and the response to drought stress by modulating trafficking and protein levels of the ABA exporter ABCG25

The phytohormone abscisic acid (ABA) regulates ion channel activity and stomatal movement in response to drought stress. Cellular ABA levels change depending on cellular and environmental conditions via modulation of its biosynthesis, catabolism and transport. Although factors involved in ABA biosynthesis and degradation have been studied extensively, how ABA transporters are modulated to fine-tune ABA levels, especially under drought stress, remains elusive. Here, we show that Arabidopsis thaliana SORTING NEXIN 2 (SNX2) proteins play a critical role in endosomal trafficking of the ABA exporter ATP BINDING CASETTE G25 (ABCG25) via direct interaction at endosomes, leading to its degradation in the vacuole. In agreement, snx2a and snx2b mutant plants showed enhanced recycling of GFP-ABCG25 from early endosomes to the plasma membrane and higher accumulation of GFP-ABCG25. Phenotypically, snx2a and snx2b plants were highly sensitive to exogenous ABA and displayed enhanced ABA-mediated inhibition of inward K+ currents and ABA-mediated activation of slow anion currents in guard cells, resulting in an increased tolerance to drought stress. Based on these results, we propose that SNX2 proteins play a crucial role in stomatal movement and tolerance to drought stress by modulating the endosomal trafficking of ABCG25 and thus cellular ABA levels.11Nsciescopu