Genetic Regulation, Environmental Cues, and Extraction Methods for Higher Yield of Secondary Metabolites in Capsicum.

Capsicum (chili pepper) is a widely popular and highly consumed fruit crop with beneficial secondary metabolites such as capsaicinoids, carotenoids, flavonoids, and polyphenols, among others. Interestingly, the secondary metabolite profile is a dynamic function of biosynthetic enzymes, regulatory transcription factors, developmental stage, abiotic and biotic environment, and extraction methods. We propose active manipulable genetic, environmental, and extraction controls for the modulation of quality and quantity of desired secondary metabolites in Capsicum species. Specific biosynthetic genes such as Pun (AT3) and AMT in the capsaicinoids pathway and PSY, LCY, and CCS in the carotenoid pathway can be genetically engineered for enhanced production of capsaicinoids and carotenoids, respectively. Generally, secondary metabolites increase with the ripening of the fruit; however, transcriptional regulators such as MYB, bHLH, and ERF control the extent of accumulation in specific tissues. The precise tuning of biotic and abiotic factors such as light, temperature, and chemical elicitors can maximize the accumulation and retention of secondary metabolites in pre- and postharvest settings. Finally, optimized extraction methods such as ultrasonication and supercritical fluid method can lead to a higher yield of secondary metabolites. Together, the integrated understanding of the genetic regulation of biosynthesis, elicitation treatments, and optimization of extraction methods can maximize the industrial production of secondary metabolites in Capsicum.

A 24-generation-old founder mutation impairs splicing of RBBP8 in Pakistani families affected with Jawad syndrome.

Jawad syndrome is a multiple congenital anomaly and intellectual disability syndrome with mutation in RBBP8 reported only in two families. Here, we report on two new families from Pakistan and identified a previously reported variant in RBBP8, NM_002894.3:c.1808-1809delTA. We could show that this mutation impairs splicing resulting in two different abnormal transcripts. Finally, we could verify a shared haplotype among all four families and estimate the founder event to have occurred some 24 generations ago.

Determination of genetic relationships among elite thermosensitive genic male sterile lines (TGMS) of rice (Oryza sativa L.) employing morphological and simple sequence repeat (SSR) markers.

A set of morphological traits and SSR markers were used to determine the genetic relationship among 12 elite thermosensitive genic male sterile (TGMS) lines developed at three different research institutions of India. Agro-morphological data recorded on 20 morphological traits revealed a wide base of genetic variation and a set of four morphological traits could distinguish most of the TGMS lines. Analysis with 30 SSR markers (20 EST-SSRs and 10 genomic SSRs) revealed 27 markers to be polymorphic, amplifying a total of 83 alleles. Each SSR marker amplified 2-6 alleles with an average of 2.76 alleles per marker and a PIC value varying from 0.54 to 0.96. Cluster analysis based on SSR and morphological data clearly differentiated the lines according to their source of origin. Correlation analysis between morphological and molecular data revealed a very poor association (r = 0.06), which could be attributed to selection pressure, genetic drift, sampling error and unknown relationship among related lines. The SSR markers discriminated the genotypes distinctly and quantified the genetic diversity precisely among the TGMS lines. Data on the yield per plant indicated that the genotypes grouping under a similar cluster showed same heterotic behaviour as compared to the genotypes from different clusters when crossed to similar pollinators.