Functional analysis of a NPC1 gene from the whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

Niemann-Pick C (NPC) disease is a neurodegenerative disorder related to cellular sterol trafficking and mutation of NPC1 gene is the main cause for this disease. The function of NPC1 have been reported in a few insects but rarely studied in hemipterans. In the present study, we investigate the function of NPC1 in a hemipteran pest, the whitefly Bemisia tabaci. It was found that B. tabaci had only one NPC1 homolog (BtNPC1), in contrast to two homologs in many other insects. BtNPC1 was ubiquitously expressed at all developmental stages and body parts of whiteflies, with the highest level in adult abdomen, and the expression of BtNPC1 was induced by cholesterol feeding. To further investigate the function of BtNPC1, leaf-mediated RNA interference experiments were carried out. Results showed that knockdown of BtNPC1 led to reduced survival of whiteflies, as well as reduced fecundity. Moreover, knockdown of BtNPC1 affected the development and metamorphosis of whitefly nymphs. Taken these together, we conclude that BtNPC1 played a crucial role in sterol-related biological processes of B. tabaci and might be used as an insecticide target for development of novel pest management approaches.

New SFT2-like Vesicle Transport Protein (SFT2L) Enhances Cadmium Tolerance and Reduces Cadmium Accumulation in Common Wheat Grains.

Cadmium (Cd) is one of the most toxic heavy metal elements to the environment, which seriously threatens the safe production of food crops. In this study, we identified a novel function of the cytomembrane TaSFT2L protein in wheat (Triticum aestivum). Expression of the TaSFT2L gene in yeast showed no transport activities for Cd, which could explain the role of TaSFT2L in metal tolerance. It was observed that increased autophagic activity in roots caused by silencing of TaSFT2L enhanced Cd tolerance. Transgenic wheat revealed that RNA interference (RNAi) lines enhanced the wheat growth concerning the increased shoot or root elongation, dry weight, and chlorophyll accumulation. Furthermore, RNAi lines decreased root-to-grain Cd translocation in wheat by nearly 68% and Cd accumulation in wheat grains by 53%. Meanwhile, the overexpression lines displayed a compromised growth response and increased Cd accumulation in wheat tissues, compared to wild type. These findings show that TaSFT2L is a key gene involved in regulation of Cd translocation in wheat, and its silencing to form transgenic wheat can inhibit Cd accumulation. This has the ability to alleviate the food chain-associated impact of environmental pollution on human health.