Genoproteomics-assisted improvement of Andrographis paniculata: toward a promising molecular and conventional breeding platform for autogamous plants affecting the pharmaceutical industry

Andrographis paniculata (Burm. f.) Wall. ex Nees. (AP) is a hermaphroditic, self-compatible, and habitual inbreeding plant. Its main bioactive component is andrographolide, which is capable of inducing autophagic cell death in some human cancer cells and helps fight HIV/AIDS. Increasing the andrographolide content by investigating the genetic mechanisms controlling its biosynthesis in order to improve and develop high-yielding cultivars are the main breeding targets for AP. However, there might exist some limitations or barriers for crossability within AP accessions. Recently, this problem was addressed in AP by using a combination of crossbreeding and biotechnology-aided genetic methods. This review emphasizes that development of a breeding platform in a hard-to-breed plant, such as AP, requires the involvement of a broad range of methods from classical genetics to molecular breeding. To this end, a phenological stage (for example, flowering and stigma development) can be simplified to a quantitative morphological trait (for example, bud or stigma length) to be used as an index to express the highest level of receptivity in order to manage outcrossing. The outcomes of the basic crossability research can be then employed in diallel mating and crossbreeding. This review explains how genomic data could produce useful information regarding genetic distance and its influence on the crossability of AP accessions. Our review indicates that co-dominant DNA markers, such as microsatellites, are also capable of resolving the evolutionary pathway and cryptic features of plant populations and such information can be used to select the best breeding strategy. This review also highlights the importance of proteomic analysis as a breeding tool. In this regard, protein diversification, as well as the impact of normal and stress-responsive proteins on morphometric and physiological behaviors, could be used in breeding programs. These findings have immense potential for improving plant production and, therefore, can be regarded as prospective breeding platforms for medicinal plants that have an autogamous mode of reproduction. Finally, this review suggests that novel site-directed genome editing approaches such as TALENs (Transcription Activator-Like Effector Nucleases) and CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein-9 nuclease) systems together with other new plant breeding technologies (NPBT) should simultaneously be taken into consideration for improvement of pharmaceutical plants.

Keywords: Andrographolide, xenogamy, crossbreeding, transcriptome analysis, metabolic pathways, molecular plant breeding

Alireza Valdiani, Daryush Talei, Surrinder K. Lattoo, Rodomiro Ortiz, Søren

Kjærsgaard Rasmussen, Jacqueline Batley, Mohd Yusop Rafii, Mahmood

Maziah, Kallevettankuzhy K. Sabu, Rambod Abiri, Suchirat Sakuanrungsirikul

& Soon Guan Tan

To cite this article: Alireza Valdiani, Daryush Talei, Surrinder K. Lattoo, Rodomiro

Ortiz, Søren Kjærsgaard Rasmussen, Jacqueline Batley, Mohd Yusop Rafii, Mahmood

Maziah, Kallevettankuzhy K. Sabu, Rambod Abiri, Suchirat Sakuanrungsirikul & Soon

Guan Tan (2017): Genoproteomics-assisted improvement of Andrographis paniculata:

toward a promising molecular and conventional breeding platform for autogamous

plants affecting the pharmaceutical industry, Critical Reviews in Biotechnology, DOI:

10.1080/07388551.2016.1260525

To link to this article: http://dx.doi.org/10.1080/07388551.2016.1260525

The use of RAPD in assessing genetic variability in Andrographis paniculata Nees

Abstract: 
RAPD analysis was done to determine intraspecific variability in Andrographis paniculata, a popular antipyretic and hepatoprotective drug used in traditional medicine in India. The accessions collected from parts of India and southeast Asia on molecular analysis revealed moderate variation within the species. Similarity measurement using UPGMA followed by cluster analysis resulted in 5 major groups based on geographical distribution that generally reflected expected trends between the genotypes. There were also important exceptions like AP48, an accession from Thailand showing close resemblance to AP38 collected from Tamil Nadu and AP29 from Assam significantly diverse from the rest of the native genotypes. The results indicated that RAPD could be effectively used for genetic diversity analysis in wild species of prospective value as it is reliable, rapid and superior to those based on pedigree information.

Published in:
Current Science (Bangalore) 76: 833-835

Active principle content and isozymes of Andrographis paniculata Nees (Kalmegh)

Abstract
Germplasm collection of Andrographis paniculata Nees (Kalmegh), a medicinal herb endowed with curative properties against a variety of ailments, was carried out from various parts of south Asia. The germplasm was reared in a field plot under identical conditions and then seeds were collected and used for the present study. Seed progenies of 15 accessions were analysed at 15 loci representing 8 enzyme systems. On an average 5.4 loci (36.00%) were found to be polymorphic (P) and mean observed number of alleles per locus (A) was 1.41. Average observed heterozygocity (Ho) was 0.406 and expected value (He) was 0.233 showing moderate level of genetic variation among different accessions. Product synthesis did not correlate with allelic variations in any of the accessions but an accession AP36 accumulating significant concentration (1.47% dry weight) of andrographolide in the leaves may be potentially useful for breeding and cultivar development.

Published in:
Journal of Medicinal and Aromatic Plant Sciences 23 (2001) 637-647.

PhD Thesis: Intraspecific variations in Andrographis paniculata Nees

Abstract: For the biodiversity- rich developing countries in the tropics, chemical and genetic prospecting of their plant genetic resources is a priority area not only to fish out genotypes/molecules of potential economic importance but also to add value to them. The present study essentially directed towards this objective, involves analysis of intraspecific variations in Andrographis paniculata Nees [കിരിയാത്ത്] (Acanthaceae), an important medicinal plant of India, presumably having its centre of origin and diversity in southern India and Sri Lanka. Specifically, the study is directed to: (i) elucidate biology of A. paniculata by understanding distribution, habitat, phenology of flowering/fruiting, cytology, breeding system and seed dormancy/ germination of the species; (ii) quantify the amount of genetic variability within A. paniculata and its patterns of interpopulation differentiation; (iii) assess the significance of inbreeding and gene flow to the level and pattern of diversity presently observed in A. paniculata; (iv) test the hypothesis that genetic distance can be significantly correlated with geographical distance; (v) identify superior genotype(s) with increased biomass and product (andrographolide) synthesis; and (vi) suggest conservation and utilization/improvement strategy for the species based on the data generated. Studies on biology of the species revealed that the plant is naturally self-pollinating, but possibility for cross-pollination could not be entirely ruled out. Intraspecific variation of A. paniculata was analysed using quantitative traits, isozyme and random amplified polymorphic DNA (RAPD) markers. The three approaches differed in the amount of variation detected. Analysis of the ten morphological characters revealed considerable diversity at inter-population level. Variation in the active principle (andrographolide) content was moderate with maximum concentration on dry weight basis (1.47%) was recorded in a population from Tamil Nadu (AP36) with a mean value of 0.95%. Product concentration did not correlate with allelic variations in any of the populations but AP36, with the highest concentration (in the leaves) averaged through three generations may help development of a cultivar.

RAPD assay revealed the highest polymorphism among the three markers tested. Twentyfive random primers generated an average of 1.61 bands (alleles) per primer (locus) with a mean polymorphism of 0.71. Isozymes on the other hand were analysed at 15 loci representing 8 enzyme systems. On an average the mean observed number of alleles per locus was 1.37 and the proportion of polymorphic loci was 0.32. Genetic differentiation estimated by Nei's distances suggested a common gene pool for the populations collected from Kerala while those from Tamil Nadu and elsewhere from India revealed more divergence. More or less, exotic populations exhibited similarity to Tamil Nadu populations which may shed light on their origin. In general, the genetic clustering derived from isozyme and RAPD data was in agreement with the geographical locations/distances. Further analysis of the two natural populations (Sirumalai and Nallamalai) collected from geographically isolated areas using Nei's distance and fixation indices indicated substantial divergence at the sub population level. This pointed out varied drift and bottleneck effects and differential gene flow between them. Local isolation, either natural or artificial, also promotes divergence of the populations. Further more, the within- populations diversity was significantly different between populations, indicating that evolutionary potential is not evenly distributed amongst populations. Regarding conservation of representative populations of A. paniculata, caution must be exercised due to sizeable differentiation at the local and withinpopulation levels. For practical conservation purpose and maintenance of maximum genetic variation within existing populations, outright collection of all the plants before seed set in a given locality by the local plant collectors should be discouraged.