Mobilization and synthesis of seed storage and LEA proteins during natural priming of Buddleja cordata and Opuntia tomentosa

Abstract

Background: In crop plants, the induction of seed storage protein mobilization and synthesis of LEA family proteins has been extensively described.Question: Natural priming promotes mobilization and synthesis of seed storage and LEA proteins in wild plants?Species studied: Buddleja cordata and Opuntia tomentosa. Study site: Reserva Ecológica del Pedregal de San Angel (REPSA).Methods: Natural priming treatments were applied to B. cordata and O. tomentosa seeds during one and six months respectively. Phosphorylated proteins fractions were obtained by affinity chromatography from control and treated seeds. Differences in protein pattern between control and treated seeds were determined by electrophoresis and the treated seed proteins were identified by LS/LS/MALDITOF. Results: The phosphorylated fraction of B. cordata treated seeds presented two proteins that were absent in the control protein fraction. These two proteins were identified as two different 11S globulins. The phosphorylated fraction of O. tomentosa treated seeds also presented two proteins that were absent in the control protein fraction. These two proteins were identified as a 12S globulin and a LEA protein.Conclusion: Seeds are subjected to changes in soil water content during their permanence in soil; this natural priming process promotes mobilization and synthesis of storage and LEA proteins that are involved in stress resistance.