Proteinase Inhibitor Synthesis in Tomato Leaves

Abstract

Soluble chemical derivatives of chitin and chitosan including ethylene glycol chitin, nitrous acid-modified chitosan, glycol chitosan, and chitosan oligomers, produced from chitosan by limited hydrolysis with HCl, were found to possess proteinase inhibitor inducing activities when supplied to young excised tomato (Lycopersicon escuekxtum var Bonnie Best) plants. Nitrous acid-modified chitosans and ethylene glycol chitin exhibited about 2 to 3 times the activity of acid hydrolyzed chitosan and 15 times more activity than glycol chitosan. The parent chitin and chitosans are insoluble in water or neutral buffers and cannot be assayed. Glucosamine and its oligomers from degree of polymerization = 2 through degree of polymerization = 6 were purified from acid-fragmented chitosan and assayed. The monomer was inactive and dimer and trimer exhibited weak activities. Tetramer possessed higher activity and the larger pentamer and hexamer oligomers were nearly as active as the total hydrolyzed mixture. None of the fragments exhibited more than 2% acetylation (the limits of detection). The contents of the acid-fragmented mixture of oligomers was chemically N-acetylated to levels of 13% and 20% and assayed. The N-acetylation neither inhibited nor enhanced the proteinase inhibitor inducing activity of the mixture. These results, along with recent rmdinps by others that chitinases and chitosanases are present in plants, provide

Chitin and chitin-related compounds in plant–fungal interactions

“…These reactions include the following: ion flux variations, cytoplasmic acidification, membrane depolarisation and protein phosphorylation (Felix et al 1993, 1998), chitinase and glucanase activation (Roby et al 1987; Tayeh et al 2015), lignification (Kawasaki et al 2006; Ali et al 2014), generation of reactive oxygen species (ROS) (Kuchitsu et al 1995), biosynthesis of jasmonic acid (JA) (Nojiri et al 1996), and phytoalexins (Ren and West 1992; Yamada et al 1993), and the expression of early responsive and defence-related genes (Minami et al 1996; Libault et al 2007). Moreover, chitosan induces proteinase inhibitors (Walker-Simmons and Ryan 1984), phytoalexin biosynthesis (Hadwiger and Beckman 1980) and callose formation (Köhle et al 1985) in dicot species. The plants’ response to chitin, chitosan and the derived oligosaccharides depends on the acetylation degree (Akiyama et al 1995; Cord-Landwehr et al 2016; Li et al 2016) and the degree of polymerisation (Walker-Simmons and Ryan 1984; Li et al 2016).…”

“…Moreover, chitosan induces proteinase inhibitors (Walker-Simmons and Ryan 1984), phytoalexin biosynthesis (Hadwiger and Beckman 1980) and callose formation (Köhle et al 1985) in dicot species. The plants’ response to chitin, chitosan and the derived oligosaccharides depends on the acetylation degree (Akiyama et al 1995; Cord-Landwehr et al 2016; Li et al 2016) and the degree of polymerisation (Walker-Simmons and Ryan 1984; Li et al 2016). of these compounds.…”

Size, acetylation and concentration of chitooligosaccharide elicitors determine the switch from defence involving PAL activation to cell death and water peroxide production in Arabidopsis cell suspensions

“…Chitosan-derived oligosaccharides elicit defence responses in different plants, mostly dicots such as the accumulation of phytoalexins in pea pods (Hadwiger and Beckman 1980), in suspension-cultured soybean cells (Kohle et al 1984), parsley cells (Conrath et al 1989), the synthesis of ROS (Lee et al 1999), the accumulation of defence-related proteinase inhibitors in tomato and potato leaves (Walker-Simmons andRyan 1984, Peñ a-Cortes et al 1988), the synthesis of callose in suspension-cultured parsley (Conrath et al 1989), tomato (Grosskopf et al 1991) and Catharanthus roseus cells (Keen 1975). Whether chitosans interact with a specific membrane receptor is not known, but the early activation of a MAP kinase cascade seems to be a common signalling pathway used by both deacetylated (Vasconsuelo et al 2003) and acetylated (Wan et al 2004) elicitors.…”

Induction of wound response genes in tomato leaves by bestatin, an inhibitor of aminopeptidases.

“…Among these genes are those encoding serine proteinase inhibitors (inhibitors I and (I; Graham et al, 1986), prosystemin (proSYS;McGurl et al, 1992), leucine aminopeptidase (LAP; Hildmann et al, 1992;Pautot et al, 1993), polyphenol oxidase (PPO; Constabel et al, 1995), an aspartic proteinase inhibitor (CDI; Hildmann et al, 1992), a cysteine proteinase inhibitor (CYS; Hildmann et al, 1992), and threonine deaminase (TD; Hildmann et al, 1992). Localized signals include oligosaccharides released from the cell walls of both plants and pathogens (Bishop et al, 1984;Darvill and Albersheim, 1984;Walker-Simmons and Ryan, 1984), whereas a systemically mobile signal has been identified as the 18-amino acid peptide systemin, which is released upon wounding by herbivore attacks (Pearce et al, 1991;Narváez-Vasquez et al, 1995). 60th classes of signaling molecules have been proposed (Farmer and Ryan, 1992;Doares et al, 1995) to mediate gene induction via a lipid-based signaling pathway called the octadecanoid pathway (Vick and Zimmermann, 1984).…”