Potential of chloroplast genome in plant breeding

Abstract

Chloroplast engineering (or chloroplast transformation technology, CTT) is a strategy consisting of inserting a transgene into the chloroplast genome of a plant instead of its nuclear genome. CTT brings advantages such as control of the site of gene insertion, high rates of transgene expression and protein accumulation, lack of transmission of the transgene via pollen due to the fact that plastid genes are maternally inherited and an absence of epigenetic effects. Tobacco remains the species most amenable to CTT to date, although chloroplast genetic engineering has also been achieved successfully in crops such as maize, tomato, cotton, potato, rice and sugar beets. Improving agricultural traits such as herbicide and pathogen resistance, resistance to drought, salt tolerance and phytoremediation potential are all promising applications. Molecular pharming is another area of chloroplast engineering with high potential; the production of a wide range of products such as vaccine antigens, pharmaceutical proteins (human somatotropin, human serum albumin, human interferon, monoclonal antibodies) and industrial proteins (avidin, beta casein, liquid crystal polymers, xylanase, anthranilate synthase) is economically beneficial in comparison with bacterial cultivation or animal cell cultures. This review summarises the current status of CCT and its potential economic impact from the viewpoint of high levels of transgene expression and high accumulation of foreign proteins.

Molecular phylogeny, character evolution, and biogeography of Aster species (Asteraceae) from the Qinghai-Tibet Plateau

“…The reason for the controversy may be that chloroplast genes are maternally inherited and can only re ect the phylogenetic information of the maternal genome in the construction of the phylogenetic tree, and the chloroplast genome is relatively conservative in evolution and does not re ect the evolutionary pathway of polyploidy [43,44]. It is also possible that evolutionary dynamics changes such as gene silencing, gene loss, gene conversion, gene invasion and inter-(intra-) genomic rearrangements occurred in multiple copies of genes during species formation, and that different genetic differentiation occurred among different species [45].…”

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

“…In addition, the accumulation of human interferon-gamma in tobacco chloroplasts reached 0.42% of total soluble protein [118]. Unlike microorganisms, plant chloroplasts can perform post-translational modifications of protein-based drugs and promote their proper folding: phosphorylation, amidation, and disulfide bond formation [119].…”

The chloroplast genome inheritance pattern of the Deli-Nigerian prospection material (NPM) × Yangambi population of Elaeis guineensis Jacq

“…Besides conventional breeding, various investigations have successfully enhanced plants’ agronomic traits by genetically modifying the nuclear genome ( Řepková, 2010 ; An et al, 2022 ). Despite their frequent use, transgene expression and hereditary agronomic characteristics are challenging to regulate because of their nuclear biparental characteristics.…”

“…Despite their frequent use, transgene expression and hereditary agronomic characteristics are challenging to regulate because of their nuclear biparental characteristics. There is also a risk that the transgene may spread among the plants’ wild relatives ( Řepková, 2010 ) through pollen dispersion. The chloroplast, one of the organelles present in the plant cell, harbors an independent genome that is small in size, and has mostly been reported to be uniparentally inherited from maternal parents, and thus has a lower risk of being spread through pollen ( Daniell, 2007 ; Birky, 2008 ; Park et al, 2021 ; An et al, 2022 ), making it a suitable genome for inheritance studies and genetic engineering.…”