Improved plastid transformation efficiency inScoparia dulcisL.

Abstract

The high expression level of industrial and metabolically important proteins in plants can be achieved by plastid transformation. The CaIA vector, a Capsicumspecific vector harboring aadA (spectinomycin resistance), is a selectable marker controlled by the PsbA promoter, and the terminator is flanked by the trnA and trnI regions of the inverted repeat (IR) region of the plastid. The CaIA vector can introduce foreign genes into the IR region of the plastid genome. The biolistic method was used for chloroplast transformation in Scoparia dulcis with leaf explants followed by antibiotic selection on regeneration medium. Transplastomes were successfully screened, and the transformation efficiency of 3 transgenic lines from 25 bombarded leaf explants was determined. Transplastomic lines were evaluated by PCR and Southern blotting for the confirmation of aadA insertion and its integration into the chloroplast genome. Seeds collected from transplastomes were analyzed on spectinomycin medium with wild types to determine genetic stability. The increased chloroplast transformation efficiency (3 transplastomic lines from 25 bombarded explants) would be useful for expressing therapeutically and industrially important genes in Scoparia dulcis L.

Application progress of plant-mediated RNAi in pest control

“…Note that a major drawback when implementing this approach is the relatively small number of plant species that can be subjected to PT, approximately 20 species, including tobacco ( Wu et al, 2017 ), tomato ( Ruf et al, 2001 ), potato ( Zhang J. et al, 2015 ), lettuce ( Ruhlman, 2014 ), soybean ( Dufourmantel et al, 2010 ), poplar ( Wu et al, 2019 ), Arabidopsis thaliana ( Ruf et al, 2019 ), and Scoparia dulcis ( Kota et al, 2019 ), due to the limitations of PT technology. Therefore, it is crucial to further expand the range of crops that can efficiently undergo PT, especially focusing on economically important crops such as rice, wheat, and cotton.…”

Advancing organelle genome transformation and editing for crop improvement

“…Engineering of the plastome was first accomplished in Chlamydomonas reinhardtii , a unicellular green alga ( Boynton et al., 1988 ), and in the higher plant tobacco ( Nicotiana tabacum ), a dicotyledonous flowering species ( Svab et al., 1990 ). Since then, the technique of plastid transformation has been extended to over 20 species of flowering plants ( Ahmad et al., 2016 ; Yu et al., 2020 ); however, reproducible protocols for achieving homoplastic offspring are currently limited to a handful of species, including tobacco, potato, tomato, cabbage, soybean, lettuce ( Bock, 2015 ), poplar ( Okumura et al., 2006 ; Wu et al., 2019 ; Xu et al., 2020 ), and licorice weed ( Muralikrishna et al., 2016 ; Kota et al., 2019 ). Cereals, the world's most important food crops, are recalcitrant to chloroplast transformation, mainly owing to the lack of a suitable selectable system, efficient shoot regeneration frequency, and cis -elements for transgene expression in non-green plastids.…”

Plastid Transformation: How Does it Work? Can it Be Applied to Crops? What Can it Offer?

“…To date, the plastids of over 20 flowering plants have been transformed [15] (Table 1). In addition to the crops mentioned above, recent successes in plastid transformation have been reported in the plant species bitter melon [16], and the medicinal plant sweet wormwood (Artemisia annua) [17] and licorice weed (Scoparia dulcis) [18,19] (Table 1). Based on these successful cases, plastid transformation should be applicable to many plant families, whether they are monocots or dicots.…”