Purification and some properties of chitinases from yam, Dioscorea opposita THUMB.

Floral nectar can affect the fitness of insect-pollinated plants, through both attraction and manipulation of pollinators. Self-incompatible insect-pollinated plants receive more insect visits than their self-compatible relatives, and the nectar of such species might face increased risk of infestation by pathogens carried by pollinators than self-compatible plants. Proteins in nectar (nectarins) play an important role in protecting the nectar, but little is known regarding nectarins in self-incompatible species. The nectarins from a self-incompatible and insect-pollinated leguminous crop, Canavalia gladiata, were separated using two-dimensional electrophoresis and analysed using mass spectrometry. The predominant nectarin gene was cloned and the gene expression pattern investigated using quantitative real-time PCR. Chitinolytic activity in the nectar was tested with different substrates. The C. gladiata nectar proteome only has one predominant nectarin, an acidic class III chitinase (CaChi3). The full-length CaChi3 gene was cloned, coding for a protein of 298 amino acids with a predicted signal peptide. CaChi3 is very similar to members of the class III chitinase family, whose evolution is dominated by purifying selection. CaChi3 was expressed in both nectary and leaves. CaChi3 has thermostable chitinolytic activity according to glycol-chitin zymography or a fluorogenic substratem but has no lysozyme activity. Chitinase might be a critical protein component in nectar. The extremely simple nectar proteome in C. gladiata disproves the hypothesis that self-incompatible species always have more complex nectar proteomes. Accessibility of nectar might be a significant determinant of the evolutionary pressure to develop nectar defence mechanisms.

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“…), Dioscorea opposita (Tsukamoto et al . ) and Ipomoea carnea (Patel et al . ) show no lysozyme activity.…”

Section: Discussionmentioning

confidence: 99%

Floral nectar of the obligate outcrossing Canavalia gladiata (Jacq.) DC. (Fabaceae) contains only one predominant protein, a class III acidic chitinase

Milne

Zhou

et al. 2017

Plant Biol J

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“…This acidic chitinase lacked lysozyme activity. An extracellular acidic chitinase purified from cucumber (19) and an acidic chitinase purified from yam tubers also lacked lysozyme activity (29). The (19) and a chitinase/ lysozyme from Parthenocissus quinquifolia (1); it did not show homology with the basic endochitinase from P. vulgaris (4).…”

Section: Discussionmentioning

confidence: 98%

“…This may be due in part to the ease with which basic proteins are separated from the bulk of the cellular protein and further purified. Nevertheless, acidic chitinases have now been isolated from in yam tubers (29), infected cucumber seedlings (18), infected tobacco (12), and tomato leaves (9). In the latex ofH.…”

Section: Discussionmentioning

confidence: 99%

The Latex of Hevea brasiliensis Contains High Levels of Both Chitinases and Chitinases/Lysozymes

Martin¹

1991

Plant Physiol.

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The latex of the commercial rubber tree, Hevea brasiliensis, was fractionated by ultracentrifugation as described by G. F. J.Moir ([1959] Nature 184: 1626-1628) into a top layer of rubber particles, a cleared cytoplasm, and a pellet that contains primarily specialized vacuoles known as lutoids. The proteins in each fraction were resolved by two-dimensional gel electrophoresis. Both the pellet fraction and cleared cytoplasm contained large amounts of relatively few proteins, suggesting that laticifers serve a very specialized function in the plant. More than 75% of the total soluble protein in latex was found in the pellet fraction. Twenty-five percent of the protein in the pellet was identified as chitinases/lysozymes, which are capable of degrading the chitin component of fungal cell walls and the peptidoglycan component of bacterial cell walls. Both the chitinase and lysozyme activities were localized exclusively in the pellet or lutoid fraction. The chitinases/lysozymes were resolved into acidic and basic classes of proteins and further purified. An acidic protein (molecular mass 25.5 kD) represented 20% of the chitinase activity in latex; this protein lacked the low level of lysozyme activity that is associated with many plant chitinases. Six basic proteins, having both chitinase and lysozyme activities in various ratios and molecular mass of 27.5 or 26 kD, were resolved. Two of the basic proteins had very high lysozyme specific activities which were comparable to the specific activities reported for animal lysozymes. Like animal lysozymes, but unlike previously characterized plant chitinases/ lysozymes, these basic chitinases/lysozymes were also capable of completely lysing or clearing suspensions of bacterial cell walls. These results suggest that laticifers may serve a defensive role in the plant.Latex is the cytoplasm of highly specialized cells known as laticifers. Most of the volume of the latex from Hevea brasiliensis is filled by rubber particles and specialized vacuoles known as lutoids (5,20). In fact, rubber has been reported to represent from 20 to 60% of the wet weight of latex (5). Laticifers are anastomosed as a result of partial hydrolysis of adjacent walls, and thus form a tube-like network or paracirculatory system through the plant (5). When wound site. This feature oflaticifers is exploited commercially to collect rubber from trees of H. brasiliensis, the sole commercial source of natural rubber.Because laticifers appear to be dedicated primarily to the biosynthesis of the isoprenoid, rubber, it is reasonable to expect the major proteins in latex to be enzymes involved in the biosynthesis of rubber. Indeed, mRNA transcripts encoding enzymes involved in rubber biosynthesis were recently shown to be 20-to 100-fold higher in laticifers than in leaves (1 1). However, transcripts of several putative defense genes including chitinases, pathogenesis-related proteins, phenylalanine ammonia-lyase, chalcone synthase, chalcone isomerase, and 5-enolpyruvylshikimate 3-phosphate synthase wer...

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“…The carbon source, nitrogen source and vitamins could decrease the chitinase, protease and lipase activities in I. farinosa simultaneously. Previous studies on chitinase, protease and lipase primarily addressed their production (St Leger et al 1986;Brzezinska et al 2013;Kuddus and Ahmad 2013), their activities ; Hu et al 1993; Lorito et al 1993;Zhang et al 2002;Tao et al 2005), their separation (Tsukamoto et al 1984;Ulhoa and Peberdy 1991;Harman et al 1993;Zhang et al 2000Zhang et al , 2002, their determination (Tao et al 2005) and the genes that encode them (Geremia et al 1993;McCreath et al 1996). There were some studies that had examined the effects of nutrition on the lipase activities (Hollenberg 1959;Semb and Olivecrona 1986;Yang et al 2006).…”

Section: Discussionmentioning

confidence: 99%

Nutritional effects on the mycelial growth and enzymatic activity ofIsaria farinosa, andHepialuslarvae growth

Liu

et al. 2016

J Appl Microbiol

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Purification and some properties of chitinases from yam, Dioscorea opposita THUMB.

Cited by 33 publications

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Floral nectar of the obligate outcrossing Canavalia gladiata (Jacq.) DC. (Fabaceae) contains only one predominant protein, a class III acidic chitinase

Floral nectar of the obligate outcrossing Canavalia gladiata (Jacq.) DC. (Fabaceae) contains only one predominant protein, a class III acidic chitinase

The Latex of Hevea brasiliensis Contains High Levels of Both Chitinases and Chitinases/Lysozymes

Nutritional effects on the mycelial growth and enzymatic activity ofIsaria farinosa, andHepialuslarvae growth

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