Transcriptome analysis unravels RNAi pathways genes and putative expansion of CYP450 gene family in cotton leafhopper Amrasca biguttula (Ishida).

Cotton Leafhopper, Amrasca biguttula is an important pest of cotton and okra in the Indian subcontinent. Presently limited genomic/transcriptomic information is available for this insect in any of open source databases. The present study reports the first assembled and annotated de novo transcriptome of cotton leafhopper. Out of 75,551 transcripts, 39,613 CDS (Coding Sequence) were predicted with 35,282 showing positive blast hits with NCBI nr database. The Gene ontology (GO) analysis annotated 7431 CDS  with KEGG pathway categorizing these CDS into 22 different functional groups. The majority of CDS were annotated in signal transduction and transport catabolism pathways. The sequence data was screened for RNAi pathway genes and presence of 37 transcripts associated with this process confirmed the existence of robust RNAi machinery. The role of core RNAi machinery genes (Dicer-2, Ago-2, Piwi and Staufen) has been validated through dsRNA feeding studies. The data resource has also been used to identify potential RNAi targets and genes associated with insecticide detoxification specifically CYP 450 family. The current study provides a useful sequence resource which can be used to initiate molecular studies in this insect with emphasis on insecticide resistance, RNAi and functional genomics.

Marker-assisted pyramiding of lycopene-ε-cyclase, ß-carotene hydroxylase1 and opaque2 genes for development of biofortified maize hybrids.

Malnutrition affects growth and development in humans and causes socio-economic losses. Normal maize is deficient in essential amino acids, lysine and tryptophan; and vitamin-A. Crop biofortification is a sustainable and economical approach to alleviate micronutrient malnutrition. We combined favorable alleles of crtRB1 and lcyE genes into opaque2 (o2)-based four inbreds viz. QLM11, QLM12, QLM13, and QLM14 using marker-assisted backcross breeding. These are parents of quality protein maize versions of two elite hybrids viz. Buland and PMH1, grown in India. Gene-based SSRs for o2 and InDel markers for crtRB1 and lcyE were successfully employed for foreground selection in BC1F1, BC2F1, and BC2F2 generations. The recurrent parent genome recovery ranged from 88.9 to 96.0% among introgressed progenies. Kernels of pyramided lines possessed a high concentration of proA (7.14-9.63 ppm), compared to 1.05 to 1.41 ppm in the recurrent parents, while lysine and tryptophan ranged from 0.28-0.44% and 0.07-0.09%, respectively. The reconstituted hybrids (RBuland and RPMH1) showed significant enhancement of endosperm proA (6.97-9.82 ppm), tryptophan (0.07-0.09%), and lysine (0.29-0.43%), while grain yield was at par with their original versions. The dissemination of reconstituted hybrids holds significant promise to alleviate vitamin-A deficiency and protein-energy malnutrition in developing countries.