No abstract

Work on improvement of durum wheat (Triticum turgidum L.) using tools of biotechnology is limited. Development of a reliable in vitro plant regeneration procedure for this important cereal is a prerequisite for its improvement by genetic transformation. Here, we report the effects of three growth regulators (GRs), 2,4‐D (2,4‐dichlorophenoxyacetic acid), picloram (4‐amino‐3,5,6‐trichloropicolinic acid), and dicamba (3,6‐dichloro‐o‐anisic acid), on callus induction and plant regeneration from scutellum cultures of four commercial durum cultivars: Ben, Maier, Munich, and Lebsock. Callus induction was obtained from isolated scutella cultured on modified Murashige and Skoog (MS) basal medium. After 4 wk of callus induction, all calli were plated on MS basal medium for regeneration. The regenerated plantlets were fertile, maintained the normal chromosome number (2n = 4x = 28) and structure as revealed by fluorescent genomic in situ hybridization (fl‐GISH), and showed no apparent somaclonal variation. Genotype and callus induction medium played a dominant role in plantlet regeneration. Dicamba proved the best GR for inducing compact callus and also gave the highest proportion (0.16) of regenerated plants across the four cultivars. Overall, Maier gave the highest proportion (0.27) of plantlet regeneration when dicamba at 2.0 mg L−1 concentration was used for initial callus induction. These results will facilitate genetic transformation work with durum wheat.

Rice is a staple and widely grown crop endowed with rich genetic diversity. As it is difficult to differentiate seeds of various rice varieties based on visual observation accurately, the harvested seeds and subsequent processed products are highly prone to adulteration with look-alike and low quality seeds by the dishonest traders. To protect the interests of importing countries and consumers, several methods have been employed over the last few decades for unambiguous discrimination of cultivars, accurate quantification of the adulterants, and for determination of cultivated geographical area. With recent advances in biotechnology, DNA based techniques evolved rapidly and proved successful over conventional non-DNA based methods to purge the problem of adulteration at commercial level. In the current review, we made an attempt to summarize the existing methods of adulteration detection and quantification in a comprehensive manner by providing Basmati as a case study to enable the traders to arrive at a quick resolution in choosing the apt method to eliminate the adulteration practice in the global rice industry.

No abstract

Bombyx mori nucleopolyhedrovirus (BmNPV) that infects the silkworm, B. mori, accounts for .50% of silk cocoon crop losses globally. We speculated that simultaneous targeting of several BmNPV essential genes in transgenic silkworm would elicit a stable defense against the virus. We introduced into the silkworm germline the vectors carrying short sequences of four essential BmNPV genes in tandem, either in sense or antisense or in inverted-repeat arrangement. The transgenic silkworms carrying the inverted repeat-containing transgene showed stable protection against high doses of baculovirus infection. Further, the antiviral trait was incorporated to a commercially productive silkworm strain highly susceptible to BmNPV. This led to combining the high-yielding cocoon and silk traits of the parental commercial strain and a very high level of refractoriness (.75% survival rate as compared to ,15% in nontransgenic lines) to baculovirus infection conferred by the transgene. We also observed impaired infectivity of the occlusion bodies derived from the transgenic lines as compared to the wild-type ones. Currently, large-scale exploitation of these transgenic lines is underway to bring about economic transformation of sericulture. R NA interference (RNAi) is a mechanism by which cells silence the expression of foreign genes. This process often provides an adaptive innate immunity against viruses where double-stranded RNAs encoded by the viruses during infection act as pathogen trigger after they are taken up by the cellular RNAi machinery (Wang et al. 2006). Alternatively, this natural defense mechanism is exploited as an antiviral therapy via the artificial inhibition of the expression of essential viral genes (Leonard and Schaffer 2006). Multiple protocols of delivery of dsRNA or of constructs encoding dsRNAs in the organism are currently under assay to combat infections of various viruses. The efficiency of the assays is still challenged by the delicate setting of the proper dosage of the RNAi, the relative longevity of the effect, the occurrence of RNAi driven toxicity, and the virus-intrinsic susceptibility. A few attempts have been made in animal and plant models where the antiviral trait was installed by transgenesis to confer stable protection to the transformed individuals and to their progeny. Successes have been reached in plants ( Bucher et al. 2006;Bonfim et al. 2007;Zhang 2010) but, to our knowledge, no case has yet been reported in animals showing a stable and robust protection against a virus after a RNAi-aided antiviral trait was introduced through germline transformation.The baculovirus, Bombyx mori nucleopolyhedrovirus (BmNPV), is a major pathogen that affects silkworm rearings and hampers silk cocoon production in Asia. In India alone .50% of silk cocoon crop losses are attributed to baculovirus infection (Khurad et al. 2006). Effective treatment against the virus has been elusive due to its sturdy nature and the lack of control strategies. Interestingly, the biology of the virus is reasonably...

No abstract

Recent advances in modern technology have led to the understanding that not all genetic information is coded into protein and that the genomes of each and every organism including insects produce non-coding RNAs that can control different biological processes. Among RNAs identified in the last decade, long non-coding RNAs (lncRNAs) represent a repertoire of a hidden layer of internal signals that can regulate gene expression in physiological, pathological, and immunological processes. Evidence shows the importance of lncRNAs in the regulation of host–pathogen interactions. In this review, an attempt has been made to view the role of lncRNAs regulating immune responses in insects.

No abstract