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Abstract

Chitinases, beta-1,3-glucanases, and ribosome-inactivating proteins are reported to have antifungal activity in plants. With the aim of producing fungus-resistant transgenic plants, we co-expressed a modified maize ribosome-inactivating protein gene, MOD1, and a rice basic chitinase gene, RCH10, in transgenic rice plants. A construct containing MOD1 and RCH10 under the control of the rice rbcS and Act1 promoters, respectively, was co-transformed with a plasmid containing the herbicide-resistance gene bar as a selection marker into rice by particle bombardment. Several transformants analyzed by genomic Southern-blot hybridization demonstrated integration of multiple copies of the foreign gene into rice chromosomes. Immunoblot experiments showed that MOD1 formed approximately 0.5% of the total soluble protein in transgenic leaves. RCH10 expression was examined using the native polyacrylamide-overlay gel method, and high RCH10 activity was observed in leaf tissues where endogenous RCH10 is not expressed. R1 plants were analyzed in a similar way, and the Southern-blot patterns and levels of transgene expression remained the same as in the parental line. Analysis of the response of R2 plants to three fungal pathogens of rice, Rhizoctonia solani, Bipolaris oryzae, and Magnaporthe grisea, indicated statistically significant symptom reduction only in the case of R. solani (sheath blight). The increased resistance co-segregated with herbicide tolerance, reflecting a correlation between the resistance phenotype and transgene expression.

Discovery and identification of candidate genes from the chitinase gene family for Verticillium dahliae resistance in cotton

“…Constitutively expressed chitinases mainly participate in physiological functions such as flower development, symbiotic interactions, seed development, somatic embryogenesis, cell division, and programmed cell death 14 41 . However, induced expression of chitinases have been recorded in response to numerous abiotic stresses, such as wounding, drought, salinity, cold, heavy metals, ozone, frost, and UV light 15 16 17 18 , as well as biotic stresses, such as infection with fungi, bacteria, viruses, viroids and nematodes 24 25 26 27 28 41 . Furthermore, the expression of chitinases is regulated by various phytohormones, such as JA, SA, ET, IAA, and CK 19 .…”

“…vesicatoria ( Xcv ) infection 52 . Co-expression of a rice basic chitinase gene ( RCH10 ) and a modified maize ribosome-inactivating protein ( MOD1 ) in transgenic rice significantly enhanced resistance to sheath blight 25 . Interestingly, transgenic plants expressing chitinase genes in combination with other PR proteins, such as a modified maize ribosome-inactivating protein or β-1, 3-glucanases, showed enhanced resistance to fungal pathogens compared to those where a single chitinase gene was introduced 25 .…”

“…Members of the chitinase family are pathogenesis-related proteins, and have been identified in almost all plants. Many of these genes have been proven to inhibit fungal growth in vitro 23 24 , and the overexpression of chitinase genes from some plants or the fungus Trichoderma species had shown to enhance resistance to fungal pathogens in a variety of transgenic plants 25 26 27 28 . However, to date, the chitinase genes in cotton have not been systematically analyzed.…”

Structure-function study of maize ribosome-inactivating protein: implications for the internal inactivation region and the sole glutamate in the active site

“…This form has been overexpressed in transgenic rice, wheat and tobacco, for increasing the resistance to plant insects such as larvae of the cigarette beetle ( Lasioderma serricorne ), the tobacco hornworm ( Manduca sexta ) and the corn earworm ( Helicoverpa zea ) (20). Co-expression of the active form and a rice basic chitinase gene in transgenic rice has also led to increased resistance to sheath blight ( Rhizoctonia solani ) (21). …”

Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice

“…However, chemical control contributes to increase health risk and financial strain on the farmer as well as being disastrous to the environment. In the absence of natural resistance, genetically modifying plants with transgenes for enhanced resistance is the most suitable alternative (Lin et al, 1995; Datta et al, 2000, 2001; Kim et al, 2003). Antifungal proteins such as chitinases and glucanases that can hydrolyse the chitin and glucan components of the fungal cell wall are the popular choices (Okubara et al, 2014).…”