Lectins from Pisum arvense seeds behave differently from storage proteins during germination in the darkness

Abstract

-The mobilization of seed proteins from Pisum arvense L. during germination in the absence of light was studied. The seeds were found to be completely consumed 22 days after germination and seedlings ceased growth after the 18 th day. SDS-PAGE indicated that the main protein bands correspond to high molecular mass storage proteins which undergo proteolysis in the initial stages of germination and are not detected after the 7 th day of germination. However, the corresponding lectin profiles were detected during the entire germination process, suggesting that these proteins are strongly resistant to seed proteolytic enzymes and should be important for seedling establishment. Furthermore, haemagglutinating activity in cotyledons was detected until 22 days after germination, indicating that the lectins remain active even in senescent cotyledons. ADDITIONAL INDEX TERMS:Lectin, protein mobilization, seed germination. LECTINAS DE SEMENTES DE Pisum arvense COMPORTAM-SE DIFERENTEMENTE DAS PROTEINAS DE RESERVA DURANTE A GERMINAÇÃO NO ESCURO

Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

“…This content increased after four days of germination and then even more when the stage of seedling was reached [12]. There's a possibility that at least a part of the increase in Abu concentration may be explained by the release of this molecule when the canonical dimmer is disrupted, when the lectins start to be consumed during final steps of germination [22]. Consequently free Abu increases in the seedlings.…”

“…Once lectins are consumed at the end of germination, it's reasonable to assume that there could be a correlation between lectin-binding substances such as Abu and the development of plant response against stress and pathogens [11,22]. …”

Storage sites in seeds of Caesalpinia echinata and C. ferrea (Leguminosae) with considerations on nutrients flow

“…Ultrastructural and histochemical evidence of proteins could be found in cotyledon cells of mature seeds in C. echinata, which showed numerous free ribosomes, rough endoplasmic reticulum, mitochondriae with developed cristae and strongly Aniline Blue Black-stained contents in cells. According to Silva et al (2000), proteins which were largely stored in sub cellular compartments and were not mobilized during the seed germination could be lecithins, these have been observed in the cotyledons of other species of Leguminosae, mainly Papilionoideae. Lecithins would act as defense proteins against predators and pathogens and would protect cotyledons while mobilization of the storage substances is being carried out (Cavada et al, 1993).…”

Seed structure in Canavalia brasiliensis Mart. ex Benth. (Leguminosae) and subcellular localization of ConBr lectin: Implications for ConBr biological functions

“…During germination, protein bodies break down into amino acids for the growing seedling, showing different patterns of protein mobilization. ConBr may have a role as storage protein, while seed lectins in legume plants may play other biological roles (Cavada et al, 1990;Moreira et al, 1993;Silva et al, 2000). This fact may justify the presence of ConBr at the endosperm.…”