Evaluation of the Chilli veinal mottle virus CP gene expressing transgenic Nicotiana benthamiana plants for disease resistance against the virus

Vegetables are an important source of income and high-value crops for small farmers. Chilli (Capsicum spp.) is one of the most economically important vegetables of Pakistan and it is grown throughout the country. It is a rich source of nutrition especially vitamins A, B, C and E along with minerals as folic acid, manganese (Mn), potassium (K) and molybdenum (Mo). Chilli possesses seven times more amount of vitamin C than an orange. Vitamin A, C and beta-carotenoids are strong antioxidants to scavenge the free radicals. Chilli production is restricted due to various biotic factors. Among these viruses, Chilli veinal mottle virus (ChiVMV) is one of the most destructive and menacing agents that inflicts heavy and colossal losses that accounted for 50% yield loss both in quality and quantity. Pathogen-Derived Resistance (PDR) approach is considered one of the effective approaches to manage plant viruses. In this study, ChiVMV was characterized on a molecular level, the coat protein (CP) gene of the virus was stably transformed into Nicotiana benthamiana plants using Agrobacterium tumefaciens. The transgenic plants were challenged with the virus to evaluate the level of resistance of plants against the virus. It was observed that the plants expressing CP gene have partial resistance against the virus in terms of symptoms’ development and virus accumulation. Translation of this technique into elite chilli varieties will be resulted to mitigate the ChiVMV in the crop as well as an economic benefit to the farmers.

Metabolic Variation among Fruits of Different Chili Cultivars (Capsicum spp.) Using HPLC/MS

Chilies are widely cultivated for their rich metabolic content, especially capsaicinoids. In our study, we determined individual sugars, organic acids, capsaicinoids, and total phenolic content in pericarp, placenta, and seeds of Capsicum annuum L., Capsicum chinense Jacq. and Capsicum baccatum L. by HPLC/MS. Dry weight varied in the cultivar ‘Cayenne’, with the first fruit having the lowest dry weight, with 4.14 g. The total sugar content and organic acid content did not vary among the fruits of all three cultivars. The cultivar ‘Cayenne’ showed differences in total phenolic and capsaicinoid content between fruits in the placenta, with the first fruit having the highest content of total phenolics (27.85 g GAE/kg DW) and total capsaicinoids (16.15 g/kg DW). Of the three cultivars studied, the cultivar ‘Habanero Orange’ showed the least variability among fruits in terms of metabolites. The content of dihydrocapsaicin, nordihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin in the seeds of the second fruit was higher than that of the first fruit of the cultivar ‘Bishop Crown’. The results of our study provided significant insight into the metabolomics of individual fruits of the same chili plant. We have thus increased our understanding of how certain metabolites are distributed between fruits at different levels of the same plant and different parts of the fruit. This could be further investigated when chilies are exposed to different environmental stresses.

Composición y aplicaciones clínicas de especies de chiles (Capsicum spp.) domesticados

El género Capsicum es originario de América Latina y se expandió a otros continentes mediante intercambio de especias. Su fruto se utiliza fresco o seco para aportar color, sabor y olor a platillos, ensaladas y salsas. Posee gran relevancia comercial a nivel mundial, siendo los principales países productores China, México y Turquía. Existen cinco especies domesticadas que son: C. baccatum, C. chinense, C. pubescens, C. frutescens y C. annuum. En general, los frutos de Capsicum disponen de gran variedad de tamaños y formas, y de acuerdo a su estado de madurez presentan cambios en las tonalidades, que van del verde a tonos amarillos, rojos y rojos intensos. Los frutos poseen compuestos bioactivos que pueden proveer efectos benéficos en la salud. El objetivo del presente trabajo fue realizar una revisión sobre los compuestos bioactivos de las diferentes especies domesticadas del género Capsicum y sus recientes aplicaciones clínicas. Debido a los componentes bioactivos de las especies de Capsicum, los estudios demuestran efectos benéficos en la prevención y tratamiento sobre enfermedades no transmisibles, efectos antiinflamatorios, control de peso, cardiovasculares, antidiabéticos, gastrointestinales y cancerígenos. Las especies de Capsicum tienen un notable papel en el campo médico debido a su capacidad de modular y modificar diversos procesos a nivel biológico.

Biostimulative effect of amino acids and green algae extract on capsaicinoid and other metabolite contents in fruits of Capsicum spp.

Background Biostimulants, such as algae extracts or amino acids, are becoming more common in agriculture because the mentality is to make plants more resistant or tolerant to negative environmental factors, rather than using synthetic chemicals (herbicides, insecticides and fungicides), whose use is decreasing year by year, forcing farmers and companies to develop new environmentally friendly products. Results In a field experiment, green algae and amino acids were tested as biostimulants on three hot pepper cultivars. A large variability was observed between the effects of the two biostimulants on the cultivars. Green algae-treated ‘Somborka’ and ‘Habanero Red Caribbean’ cultivars had 10% and 5% higher dry matter in seeds compared to control treatment. Total sugar content was negatively affected by green algae extract and amino acids in pericarp in cultivars ‘Chili AS-Red’ and ‘Habanero Red Caribbean’. Total organic acids content was positively affected by amino acid treatment in ‘Habanero Red Caribbean’ pericarp and placenta, with an increase of 5.5 g and 2.1 g/100 g DW, respectively. In terms of total phenolics, all three cultivars were positively affected by amino acid treatment, but not in each fruit part. In terms of capsaicinoid content, the greatest effect of the two stimulants was on ‘Somborka’, which varied from four (pericarp, seed) to 16 (placenta) times compared to the control. Amino acid extract decreased ‘Habanero Red Caribbean’ capsaicinoid content in placenta by about 40%. Conclusion Amino acids were found to be superior to algal extract, although the effect of both was mostly cultivar specific. For a wider use of biostimulants, it should first be tested whether they are suitable for the cultivar in order to increase and optimize the results. Graphic abstract

Transcriptional Regulation of Ripening in Chili Pepper Fruits (Capsicum spp.)

Chili peppers represent a very important horticultural crop that is cultivated and commercialized worldwide. The ripening process makes the fruit palatable, desirable, and attractive, thus increasing its quality and nutritional value. This process includes visual changes, such as fruit coloration, flavor, aroma, and texture. Fruit ripening involves a sequence of physiological, biochemical, and molecular changes that must be finely regulated at the transcriptional level. In this review, we integrate current knowledge about the transcription factors involved in the regulation of different stages of the chili pepper ripening process.

Evaluation of Anthracnose Resistance in Pepper (Capsicum spp.) Genetic Resources

Anthracnose (Colletotrichum spp.), is one of the major yield losing fungal disease in both pre- and post-harvest stage of pepper (Capsicum spp.) production worldwide. Among the Colletotrichum spp., C. acutatum has strong pathogenicity, which infects both immature and mature pepper fruit leads to severe economic losses in pepper production. Inheritance of anthracnose disease resistance was evaluated with 3738 pepper genetic resources which was collected from different countries and conserved at Korean genebank. The resistance analysis against pepper anthracnose (C. acutatum) was performed on detached mature green and red fruits under laboratory conditions by spray (non-wounding) and microinjection (wounding) inoculation methods. In the primary screening, about 261 accessions were appeared to be resistant against C. acutatum in spray inoculation. The resistant accessions were further evaluated with microinjection (wounding) inoculation method using the fungal (C. acutatum) isolate of pepper anthracnose. There were highly significant differences in the disease severity and distribution of disease rating scale, considering all the sources has significant genetic variation. Finally, the anthracnose resistant pepper accessions have been validated with cleaved amplified polymorphic sequence (CAPS) and high-resolution melting (HRM) markers in which, the CAPS and HRM marker analysis showed four types of genotypes such as resistant (R), susceptible (S), heterozygous (H) and Unidentified type (UT) or not detection. The Capsicum accessions showing high level of resistance to the pathogen could be used as source material in breeding programs for resistance to anthracnose disease.

Current and Prospective Strategies in the Varietal Improvement of Chilli (Capsicum annuum L.) Specially Heterosis Breeding

Chilli (Capsicum annuum L.) is an herbaceous crop and plays an important role as common spices and vegetables. Pepper (Capsicum spp.) is one of the most cost-effective and agricultural vegetables in the world. The most significant characteristics of peppers, as spices and in various pharmacological uses, are pungency and oleoresin (color). Cabsicum annuum L. is widely used as a medicinal herb and in the Mediterranean diet (at the present, C. annuum var. acuminatum Fingerh. and Capsicum frutescens L. are considered synonyms of C. annuum L.). Capsicum annuum includes a wide range of carotenoids including capsanthin, capsorubin, beta-carotene, cryptoxanthin, lutein, fanthophyl, and xanthophyll, and capsaicinoid. However, it remains limited in production due to the lack of development in varieties especially under severe climatic circumstances such as drought, high temperature, or salt. Some reports were provided through distinct traditional approaches for genetic improvement. A combination of traditional and molecular breeding, especially breeding for heterosis, might be a good option for developing a novel genotype for ecologically adversely affected niche adaption. This review summarizes the current chilli breeding approaches with their drawbacks and highlights some recent classical efforts for the improvement of the crop. This would be the milestone for the breeders in the planning of a successful chilli breeding program to combat the adverse ecological condition. Thus, the information gathered in this article might be considered as the cornerstone of Chilli breeders at their ongoing and sustainable future programs as well.