Moonkyung Ko1, Jung Hyun Cho1, Hyo-Hyoun Seo1, Hyun-Hwa Lee2, Ha-Young Kang1, Thai Son Nguyen1, Hyun Cheol Soh1, Young Soon Kim3, Jeong-Il Kim4. 1. Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju, 500-757, Republic of Korea. 2. Department of Biology, Chosun University, Gwangju, 501-759, Republic of Korea. 3. Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju, 500-757, Republic of Korea. youngskim@chonnam.ac.kr. 4. Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju, 500-757, Republic of Korea. kimji@chonnam.ac.kr.
Abstract
MAIN CONCLUSION: Resistance against anthracnose fungi was enhanced in transgenic pepper plants that accumulated high levels of a carboxylesterase, PepEST in anthracnose-susceptible fruits, with a concurrent induction of antioxidant enzymes and SA-dependent PR proteins. A pepper esterase gene (PepEST) is highly expressed during the incompatible interaction between ripe fruits of pepper (Capsicum annuum L.) and a hemibiotrophic anthracnose fungus (Colletotrichum gloeosporioides). In this study, we found that exogenous application of recombinant PepEST protein on the surface of the unripe pepper fruits led to a potentiated state for disease resistance in the fruits, including generation of hydrogen peroxide and expression of pathogenesis-related (PR) genes that encode mostly small proteins with antimicrobial activity. To elucidate the role of PepEST in plant defense, we further developed transgenic pepper plants overexpressing PepEST under the control of CaMV 35S promoter. Molecular analysis confirmed the establishment of three independent transgenic lines carrying single copy of transgenes. The level of PepEST protein was estimated to be approximately 0.002 % of total soluble protein in transgenic fruits. In response to the anthracnose fungus, the transgenic fruits displayed higher expression of PR genes, PR3, PR5, PR10, and PepThi, than non-transgenic control fruits did. Moreover, immunolocalization results showed concurrent localization of ascorbate peroxidase (APX) and PR3 proteins, along with the PepEST protein, in the infected region of transgenic fruits. Disease rate analysis revealed significantly low occurrence of anthracnose disease in the transgenic fruits, approximately 30 % of that in non-transgenic fruits. Furthermore, the transgenic plants also exhibited resistance against C. acutatum and C. coccodes. Collectively, our results suggest that overexpression of PepEST in pepper confers enhanced resistance against the anthracnose fungi by activating the defense signaling pathways.
MAIN CONCLUSION: Resistance against anthracnose fungi was enhanced in transgenic pepper plants that accumulated high levels of a carboxylesterase, PepEST in anthracnose-susceptible fruits, with a concurrent induction of antioxidant enzymes and SA-dependent PR proteins. A pepper esterase gene (PepEST) is highly expressed during the incompatible interaction between ripe fruits of pepper (Capsicum annuum L.) and a hemibiotrophic anthracnose fungus (Colletotrichum gloeosporioides). In this study, we found that exogenous application of recombinant PepEST protein on the surface of the unripe pepper fruits led to a potentiated state for disease resistance in the fruits, including generation of hydrogen peroxide and expression of pathogenesis-related (PR) genes that encode mostly small proteins with antimicrobial activity. To elucidate the role of PepEST in plant defense, we further developed transgenic pepper plants overexpressing PepEST under the control of CaMV 35S promoter. Molecular analysis confirmed the establishment of three independent transgenic lines carrying single copy of transgenes. The level of PepEST protein was estimated to be approximately 0.002 % of total soluble protein in transgenic fruits. In response to the anthracnose fungus, the transgenic fruits displayed higher expression of PR genes, PR3, PR5, PR10, and PepThi, than non-transgenic control fruits did. Moreover, immunolocalization results showed concurrent localization of ascorbate peroxidase (APX) and PR3 proteins, along with the PepEST protein, in the infected region of transgenic fruits. Disease rate analysis revealed significantly low occurrence of anthracnose disease in the transgenic fruits, approximately 30 % of that in non-transgenic fruits. Furthermore, the transgenic plants also exhibited resistance against C. acutatum and C. coccodes. Collectively, our results suggest that overexpression of PepEST in pepper confers enhanced resistance against the anthracnose fungi by activating the defense signaling pathways.
Authors: I A Penninckx; K Eggermont; F R Terras; B P Thomma; G W De Samblanx; A Buchala; J P Métraux; J M Manners; W F Broekaert Journal: Plant Cell Date: 1996-12 Impact factor: 11.277
Authors: Félix Juan Martínez-Rivas; Rosario Blanco-Portales; Enriqueta Moyano; Saleh Alseekh; Jose Luis Caballero; Wilfried Schwab; Alisdair R Fernie; Juan Muñoz-Blanco; Francisco Javier Molina-Hidalgo Journal: Hortic Res Date: 2022-04-22 Impact factor: 7.291
Authors: Viviane Y Baba; Adrian F Powell; Suzana T Ivamoto-Suzuki; Luiz F P Pereira; André L L Vanzela; Renata M Giacomin; Susan R Strickler; Lukas A Mueller; Rosana Rodrigues; Leandro S A Gonçalves Journal: Sci Rep Date: 2020-07-21 Impact factor: 4.379