In Vitro Genome Duplication: A Promising Way For Plantago Ovata Medicinal Plant Industry
Among the medicinal herbs in the dry and semi-arid regions of Asia, Plantago ovata has a special reputation for its mucilage. Due to population growth, decreasing natural resources and subsequently increasing demand, it needs an additional value in biomass and effective compounds of P. ovata. To face such a challenge, genome duplication is considered as a potential solution because it usually enhances biomass and secondary metabolites content. In regards, to obtain the genome duplicated plants of P. ovata, we have used colchicine and trifluralin treatments on terminal bud and seed of the plant. Flow cytometry and also chromosome counting methods were utilized to recognize as well as confirm the plants with duplicated genome, respectively. Then, to uncover the differences between the various levels of polyploidy, traits related biomass and mucilage such as the leaf, seed, spike, chloroplast, stomata, chlorophyll and carotenoid were examined.
Findings demonstrated that tetraploid plants had considerable more leaf thickness, spike length, seeds per spike, as well as seed length. The more and bigger seeds can result in increased mucilage content because seeds are the source of this component. Moreover, amount of chlorophyll (a, b, and total), carotenoids as well as chloroplast number in guard cells increased in 4x as compared with 2x plants. Unlike stomata density, stomata size in 4x plants was bigger than 2x type which can lead to more gas exchange and afterward improved photosynthesis. Thus, it was deduced that leaf, seed, spike, chloroplast, stomata, chlorophyll and carotenoid attributes can be considered as useful parameters to isolate of the genome duplicated plants in P. ovata. In addition, 0.3% colchicine for 24 h as well as 22.5% trifluralin for 72 h, were found as the optimum treatments for the tetraploidy inducing in P. ovata. Since the tetraploidy superiority was seen in second generation, our genome duplicated stocks are the possible materials to enhance the biomass and content of effective compounds, especially mucilage, in P. ovata.
Plantago ovata can be recognized as an important medicinal herb in many parts of the world. In fact, P. ovata is considered as an economic plant with high sold abroad value in the pharmacy industries. However, changing drug trends has led to an increase in demand for biomass and content of effective compounds in P. ovata. Since genome duplication affects the plant size and its secondary metabolites profile, chromosome doubling was found as a promising way in plant breeding and biotechnology.
For medicinal plants, polyploids are considered the more valuable because they exhibit an additional extent in yield and bioactive compounds. For example, it was reported that alkaloid and parthenolide content is higher in roots and leaves of Datura stramonium tetraploids and flowers of Tanacetum parthenium tetraploids, respectively. In general, genome duplication can result in larger bulk, larger flowers, delays in flowering, prolongation of the flowering period, apomixes, larger fruits, and greater secondary metabolite production and yield. In selective breeding, genome duplication can restore the fertility in interspecific hybrids and save the time in breeding schemes. Consequently, polyploids have important pharmaceutical and agronomic advantages. So that, polyploids related to Avena sativa, Saccharum officinarum, Solanum tuberosum, Triticosecale, Triticum aestivum, Coffea Arabica, Fragaria ananassa, Nicotiana tabacum plants demonstrated the remarkable beneficial for commercial values.
Given the above, we firstly produced the genome duplicated plants for P. ovata via colchicine & trifluralin treatments. And also, our findings represented the efficient premeasures to identify the real polyploids.
