S01 - Session O6 - Molecular strategies for prickly pear (Opuntia sp) study and its improvement

Authors: Andres Cruz-Hernandez *, Sergio Guerrero-Garibay , Fernando Olvera-Martínez, Daira Aceves-Monreal, Pedro Luis Lopez de Alba

Nopal is a crop native to Mexico, which can grow under extreme cultivation conditions. It is an ancestral crop that contributed to the establishment of Mexican civilization and today can contribute to the self-sufficiency and food security of Mexicans. Prickly pear (cactus fruit) shows great variability in its anatomy, which makes it attractive for marketing. However, they have two disadvantages: a high number of seeds of large size, and the presence of thorns. It would be of great interest to identify those factors that generate these characteristics. To date, reports related to these characteristics are scarce or nil. The objective of this work is to generate information to understand the development of the fruit and its different characteristics at the molecular level, which could be applicable toe genetic improvement. Four stages of development were collected: flower bud, fertilized bud, green fruit and ripe fruit, of the Reina morphospecies (intermediate ripening behavior). The expression of microRNAs in prickly pear tissues was analyzed with microarray hybridization and by NGS transcriptome analysis. Through computational work, the exclusive microRNAs for the developmental stages of prickly pear were selected from the analysis of aproximadetly 20,000 miRNAs. A total of 43 miRNAs with 26 different targets were identified in relation to fruit development from flower induction. It highlighted the importance of miR172 and miR395 as key candidates at fruit ripening time. Also, miR397 was identified as a candidate for the generation of varieties with reduced seed production. The mechanism of action of the selected microRNAs was successfully validated in other plants.