Overexpression of ghr-miR166b generates resistance against Bemisia tabaci infestation in Gossypium hirsutum plants

Abstract

In silico identified Gossypium hirsutum ghr-miR166b shows multi-compatible targets in mitochondrial ATP synthase of Bemisia tabaci. Its overexpression in planta has the potential to act as a biopesticide in reducing B. tabaci population, and consequently the spread of whitefly-transmitted plant viruses. Whiteflies (B. tabaci) are hemipterous insects that act as a vector to transmit plant viruses causing enormous losses to the plants. In the present study, G. hirsutum-encoded miRNAs targeting expressed sequence tags (ESTs) of B. tabaci, based on sequence complimentarity and miRNA-target mRNA thermodynamics, were in silico identified. Out of 108 G. hirsutum miRNAs, 55 targeted the protein encoding ESTs. Among them, ghr-miR166b was selected owing to its intrinsic affinity for ATP synthase. Its functional role was validated following expression of ghr-MIR166b (precursor) sequence in G. hirsutum cv. HS6 plants through Agrobacterium-mediated transformation. Total of seven independent transformed (T) G. hirsutum lines were obtained. The transcript level of ghr-MIR166b in the transgenic lines was observed to be 2.0- to 17-fold higher as compared to non-transformed plants. Northern-blot analysis of small RNAs isolated from the transgenic plants confirmed the presence of the ghr-miR166b. After feeding on the leaves of transgenic line (HS6-166-30) having highest level of ghr-miR166b expression, B. tabaci population was reduced up to 91% as compared to non-transformed leaves. Further, in the whole plant assay, a maximum of 78% B. tabaci mortality was observed in the same line, while there was an increase in B. tabaci population on the non-transformed plants. Our results revealed that ghr-miR166b supposedly targeting ATP synthase gene of B. tabaci, and subsequently its overexpression in planta has potential to act as biopesticide for reducing B. tabaci population and consequently spread of whitefly transmitted viruses.

Diversity and recombination analysis of Cotton leaf curl Multan virus: a highly emerging begomovirus in northern India

“…Among them, Begomovirus , the largest and most important genus of the family Geminivirideae , presently comprises of > 200 species. They are transmitted by Bemisia tabaci (whitefly) insect vector and infect dicotyledonous plants [8, 9]. Five species of begomovirus complexes i.e., Cotton leaf curl Multan virus (CLCuMuV), Cotton leaf curl Bangalore virus (CLCuBaV), Cotton leaf curl Kokhran virus (CLCuKoV), Cotton leaf curl Gezira virus (CLCuGeV) and Cotton leaf curl Alabad virus (CLCuAlV) are presently associated with CLCuD [10].…”

“…The CLCuD-affected cotton plants show characteristic symptoms of thickening and darkening of veins, curling of leaves (mostly upward), development of outgrowths (enations) on the lower side of leaves and stunted growth of plants. This disease spreads through whitefly in a persistent, circulative manner [9, 11].…”

High Density Planting System of Cotton in India: Status and Breeding Strategies

“…The major diseases of cotton which are prevalent in most part of the cotton growing countries in the world were reported to inflict a damage ranging from 10 to 30% and it may be more when favorable conditions prevail for the spread of the pathogens which culminates in cotton farmers spending huge cost to keep the biotic stress under control [55].…”

Transgenic rice overexpressing insect endogenous microRNA csu‐novel‐260 is resistant to striped stem borer under field conditions

“…Although most studies on RNAi‐mediated insect‐resistant plants are based on dsRNA (Liu et al ., 2020), limited studies have suggested that microRNA (miRNA)‐mediated RNAi is also practically applicable for insect‐resistant plant development. MiRNA‐mediated RNAi plants can be classified into four types based on the origin of miRNA effectors: artificially designed miRNAs (Guo et al ., 2014), natural insect miRNAs (Jiang et al ., 2017), natural plant miRNAs (Wamiq and Khan, 2018) and modified insect pre‐miRNAs (Bally et al ., 2020).…”