The multiple functions of plant serine protease inhibitors

Abstract

Moreover, many plants express a number of different PIs and it was unknown if these proteins work synergistically as defenses or if they also have other functions. We recently identified four serine PIs (SPI) of Solanum nigrum and demonstrated that they differ substantially in substrate specificity, accumulation patterns, and their effect against different natural herbivorous insects in field-and glasshouse experiments. These differences suggest that SPIs have at least partially diversified to provide protection against different attackers. Although we could not detect effects on plant development or growth when silencing SPIs, gene-and tissue-specific expression patterns suggest multiple functions in generative tissues, including a possible involvement in development. The Function of PIs, Their Diversity and EvolutionDirected and tightly controlled proteolysis is a key cellular requirement for all domains of life. In Arabidopsis, the more than 800 proteases from 60 families highlight the importance of proteolytic processes in plants.

Purification, characterization, and bioassay of putative protease inhibitors from Hevea brasiliensis latex

“…In accordance with the literature, serine and cysteine protease inhibitors are two types found in large quantities in the cells (Habib & Fazili, 2007;Mendoza-Blanco & Casaretto, 2012;Popovic et al, 2013). Both of these PI are part of cell homeostasis playing a role in plant defense against pathogens (Hartl et al, 2011, Kim et al, 2009.…”

Prospecção de descritores para seleção de genótipos de amendoim tolerantes a pragas de grãos armazenados

“…Proteínas de defesa têm sido reportadas na literatura, entre elas os inibidores proteicos (IPs), quitinases, proteínas inativadoras de ribossomo (RIPs), arcelinas, vicilinas, leguminas, lectinas, defensinas, tioninas e proteínas de transferências de lipídeos (LTPs) (Habib & Fazili, 2007;Pereira et al, 2007;Hartl et al, 2011;Lima & Morais, 2013). Esses inibidores formam um complexo inibindo, parcial ou totalmente, suas enzimas cognatas (Habib & Fazili, 2007) e exercem papel preponderante no melhoramento de plantas para resistência a insetos, tanto por meio convencional quanto biotecnológico, em razão da sua capacidade de inibir enzimas hidrolíticas (Pereira et al, 2007;Oliveira et al, 2009;De Paola et al, 2012 Vários autores reportam que os IPs (proteases e α-amilases) atuam como defensivos naturais contra insetos, principalmente das Ordens Lepidoptera e Coleoptera, em razão dos efeitos deletérios provocados, incluindo redução de fecundidade, perda de peso, aumento da mortalidade e algumas deformações, em virtude da redução da atividade proteolítica do trato digestivo, limitando a assimilação de nutrientes (Haq et al, 2004;Macedo et al, 2010).…”

Two legume defense proteins suppress the mobility of nasopharyngeal carcinoma cells

“…Though the defending mechanism of plants is not as distinct as that in mammals, they definitely have a defense system against pathogens and plants under threat can react with alterations in morphology, structural features and production of chemicals to augment resistance against the threat 1 . The expression of defense proteins, like lectins/hemagglutinins 2,3 , anti-fungal proteins 4 , ribosome inactivating proteins 5 , protease inhibitors 6 , etc., is one of the common strategies adopted by plants. As one of the defense proteins in plants, protease inhibitors have been isolated from a variety of plants, like Moringa oleifera flowers 7 , buckwheat 8 , legumes and Lawsonia inermis 9 .…”

“…Trypsin inhibitors are the kind of inhibitors that could reduce the availability of trypsin which is a serine protease that cleaves proteins specifically at the C-terminus of lysine or arginine residue 10 . Protease inhibitors are suspected to protect plants from herbivorous insects by attenuating the activity of digestive proteases 6 . Vulnerable organs of plants, like seeds, usually possess abundant protease inhibitors to prevent tissues from undesirable degradation 11 .…”