Tissue culture and generation of autotetraploid plants of Sophora flavescens Aiton

An update on biotechnological intervention mediated by plant tissue culture to boost secondary metabolite production in medicinal and aromatic plants

Since prehistoric times, medicinal and aromatic plants (MAPs) have been employed for various therapeutic purposes due to their varied array of pharmaceutically relevant bioactive compounds, i.e. secondary metabolites. However, when secondary metabolites are isolated directly from MAPs, there is occasionally very poor yield and limited synthesis of secondary metabolites from particular tissues and certain developmental stages. Moreover, many MAPs species are in danger of extinction, especially those used in pharmaceuticals, as their natural populations are under pressure from overharvesting due to the excess demand for plant-based herbal remedies. The extensive use of these metabolites in a number of industrial and pharmaceutical industries has prompted a call for more research into increasing the output via optimization of large-scale production using plant tissue culture techniques. The potential of plant cells as sources of secondary metabolites can be exploited through a combination of product recovery technology research, targeted metabolite production, and in vitro culture establishment. The plant tissue culture approach provides low-cost, sustainable, continuous, and viable secondary metabolite production that is not affected by geographic or climatic factors. This study covers recent advancements in the induction of medicinally relevant metabolites, as well as the conservation and propagation of plants by advanced tissue culture technologies.

Chromosome doubling of Sedum alfredii Hance: A novel approach for improving phytoremediation efficiency

Sedum alfredii Hance is a cadmium (Cd)/zinc (Zn) hyperaccumulator native to China. However, its relatively low biomass restricted the large-scale application for heavy metal contamination remediation. The chromosome set doubling of S. alfredii in vitro was achieved by 0.1%-0.2% (W/V) colchicine treatment. The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants (CSD) were identified based on the obvious different sharp peak. A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots. The results suggested that S. alfredii is a mixoploid. Compared with the wild type plants (WT), CSD exhibited typical "gigas" characteristics in morphology including stem thickness, root hair production, number of leaves and size of stoma guard cell. Fresh weight and dry weight of CSD were increased to 1.62-2.03-fold and 2.26-3.25-fold of WT. And Cd content of CSD showed a 17.49%-42.82% increase and 59% increase under tissue culture and field condition, accordingly. In addition, the TF and in BCF of CSD were 2.37- and 1.59-fold of WT, respectively. These results proved that it is feasible to promote phytoextraction efficiency of S. alfredii in Cd contaminated soils through chromosomal engineering, which provides a novel approach for hyperaccumulator application in phytoremediation.

In vitro Induction and Generation of Tetraploid Plants of Sophora tonkinensis Gapnep

Background:

Sophora tonkinensis Gapnep. is an important medical plant in China. Early researches of S. tonkinensis were focused on rapid propagation and quality analysis of in vitro tissue culture plantlet, and still no research focuses on the plant breeding of and there were no excellent varieties for artificial cultivation of S. tonkinensis.

Objective:

To set up a method to generate and select the best varieties of S. tonkinensis by polyploid breeding after induction by colchicine treatment.

Materials and Methods:

The adventitious buds were submerged in different concentrations of aqueous colchicine solution for different lengths of time to induce polyploidy in the plants, and the induced buds were identified by root-tip chromosome determination and leaf characteristics comparison. The contents of matrine and oxymatrine of radix ex rhizoma in 13 selected tetraploid lines were collected after 90 days in vitro rooting culture and were evaluated to provide evidence of good qualities of tetraploid S. tonkinensis.

Results:

The results showed that the highest percentage of tetraploid induction was 23.33% and occurred in the 0.2% (w/v) colchicine treatment for 30 h. Fifty lines of tetraploid plants were obtained and 12 of the 13 selected tetraploid lines exhibited higher productivity of total contents of matrine and oxymatrine when compared to controls.

Conclusion:

The data demonstrate that polyploidy induction can be beneficial for improving the medicinal value of S. tonkinensis.

SUMMARY

Colchicine has a good in vitro induction effect on the tetraploid plants of Sophora tonkinensis

The leaf indices and stomatal apparatus of tetraploid plants were slightly larger than diploid plants

The total content of matrine and oxymatrine of some tetraploid lines for 90-day-old in vitro rooting culture was higher than the diploid.

Abbreviations used: MS medium: Murashige and Skoog medium; BAP: 6-benzylaminopurine; NAA: A-naphthaleneacetic acid; IAA: Indole-3-acetic acid; KT: Kinetin; IBA: Indole-3-butyric acid; ABT: Rooting power.

Evolutionary response to the Qinghai-Tibetan Plateau uplift: phylogeny and biogeography of Ammopiptanthus and tribe Thermopsideae (Fabaceae)

Previous works resolved diverse phylogenetic positions for genera of the Fabaceae tribe Thermopsideae, without a thoroughly biogeography study. Based on sequence data from nuclear ITS and four cpDNA regions (matK, rbcL, trnH-psbA, trnL-trnF) mainly sourced from GenBank, the phylogeny of tribe Thermopsideae was inferred. Our analyses support the genera of Thermopsideae, with the exclusion of Pickeringia, being merged into a monophyletic Sophoreae. Genera of Sophoreae were assigned into the Thermopsoid clade and Sophoroid clade. Monophyly of Anagyris, Baptisia and Piptanthus were supported in the Thermopsoid clade. However, the genera Thermopsis and Sophora were resolved to be polyphyly, which require comprehensive taxonomic revisions. Interestingly, Ammopiptanthus, consisting of A. mongolicus and A. nanus, nested within the Sophoroid clade, with Salweenia as its sister. Ammopiptanthus and Salweenia have a disjunct distribution in the deserts of northwestern China and the Hengduan Mountains, respectively. Divergence age was estimated based on the ITS phylogenetic analysis. Emergence of the common ancestor of Ammopiptanthus and Salweenia, divergence between these two genera and the split of Ammopiptanthus species occurred at approximately 26.96 Ma, 4.74 Ma and 2.04 Ma, respectively, which may be in response to the second, third and fourth main uplifts of the Qinghai-Tibetan Plateau, respectively.