Polymorphism of CLE gene sequences in potato

CLE (CLV3/ESR) is one of the most important groups of peptide phytohormones: its members regulate the development of various plant organs and tissues, as well as interaction with some parasites and symbionts and response to environmental factors. In this regard, the identification and study of the CLE genes encoding the peptides of this group in cultivated plants are of great practical interest. Relatively little is known about the functions of CLE peptides in potato, since the CLE genes of the potato Solanum phureja Juz. et Buk. were characterized only in 2021. At the same time, potato includes plenty of tuberous species of the genus Solanum L., both wild and cultivated, and the diversity of its forms may depend on differences in the sequences of CLE genes. In this work, we performed a search for and analysis of the CLE gene sequences in three wild potato species (S. bukasovii Juz., S. verrucosum Schltdl., S. commersonii Dunal) and four cultivated species (S. chaucha Juz. et Buk., S. curtilobum Juz. et Buk., S. juzepczukii Juz. et Buk., S. ajanhuiri Juz. et Buk.). In total, we identified 332 CLE genes in the analyzed potato species: from 40 to 43 genes of this family for each potato species. All potato species taken for analysis had homologues of previously identified S. phureja CLE genes; at the same time, the CLE42 gene, which is absent from the S. phureja genome, is present in all other analyzed potato species. Polymorphism of CLE proteins of S. commersonii is significantly higher than that of other analyzed potato species, due to the fact that S. commersonii grows in places outside the growing areas of other potato species and this potato is probably not one of the ancestors of cultivated potato. We also found examples of polymorphism of domains of CLE proteins that carried different functions. Further study of potato CLE proteins will reveal their role in development, including regulation of productivity in this important agricultural crop.

Potato Landraces and Their Wild Relatives in 3 Micro-centers of Diversity in Ecuador: Farmers' Perception and Ecogeography

Ecuador is one of the centers of diversity for wild and cultivated potatoes. Three micro-centers of diversity were previously identified based on germplasm collecting passport data of potato landraces and their wild relatives. The objective of this study was to understand the potential hybridization dynamic of the genetic diversity present in situ in these micro-centers (provinces of Carchi, Chimborazo and Loja in Ecuador) by means of: 1. Reviewing the possibility of an eventual genetic cross within intercropped potato landraces through surveys to local producers; 2. Reviewing the possibility of potato landraces crossing with their wild relatives, also according to local producers; and 3. Map the actual geographic location of recent collections of potato landrace and wild potato relatives in the study areas. Information from farmers and eco-geographic data demonstrated that there is no potential crossing between wild and cultivated potato species. Probably the existing genetic variability in Ecuador has been accumulated since the historical movement of potato landraces by American ancestors from the center of origin in Peru and Bolivia and the continuum knowledge and seed sharing besides the conscious and unconscious selection of potato landraces by local farmers for centuries. Additionally, we discuss options to conserve both cultivated and wild potato species in Ecuador due to apparent current genetic erosion processes.

Transcriptional and proteomic insights into phytotoxic activity of interspecific potato hybrids with low glycoalkaloid contents

Background Glycoalkaloids are bioactive compounds that contribute to the defence response of plants against herbivore attack and during pathogenesis. Solanaceous plants, including cultivated and wild potato species, are sources of steroidal glycoalkaloids. Solanum plants differ in the content and composition of glycoalkaloids in organs. In wild and cultivated potato species, more than 50 steroidal glycoalkaloids were recognized. Steroidal glycoalkaloids are recognized as potential allelopathic/phytotoxic compounds that may modify the growth of target plants. There are limited data on the impact of the composition of glycoalkaloids on their phytotoxic potential. Results The presence of α-solasonine and α-solamargine in potato leaf extracts corresponded to the high phytotoxic potential of the extracts. Among the differentially expressed genes between potato leaf bulks with high and low phytotoxic potential, the most upregulated transcripts in sample of high phytotoxic potential were anthocyanin 5-aromatic acyltransferase-like and subtilisin-like protease SBT1.7-transcript variant X2. The most downregulated genes were carbonic anhydrase chloroplastic-like and miraculin-like. An analysis of differentially expressed proteins revealed that the most abundant group of proteins were those related to stress and defence, including glucan endo-1,3-beta-glucosidase acidic isoform, whose expression level was 47.96× higher in potato leaf extract with low phytotoxic. Conclusions The phytotoxic potential of potato leaf extract possessing low glycoalkaloid content is determined by the specific composition of these compounds in leaf extract, where α-solasonine and α-solamargine may play significant roles. Differentially expressed gene and protein profiles did not correspond to the glycoalkaloid biosynthesis pathway in the expression of phytotoxic potential. We cannot exclude the possibility that the phytotoxic potential is influenced by other compounds that act antagonistically or may diminish the glycoalkaloids effect.