Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Proceedings
Publication Acceptance Date: July 26, 2013
Publication Date: July 26, 2013
Citation: Lakshman, D.K., Natarajan, S.S., Mitra, A. 2013. Lactoferrin derived resistance against plant pathogen in transgenic plants. Journal of Agricultural and Food Chemistry. 61:11730-11735. Interpretive Summary: Diseases caused by soilborne plant pathogens are responsible for the largest percentage of loss in commercial ornamental and vegetable production. Soilborne pathogens were once successfully controlled by methyl bromide - a pesticide recently banned due to environmental concerns. On the other hand, control of the pathogen with conventional pesticides is sometimes unreliable. An integrated approach using conventional control methods with introduced genetic resistance has been shown by others to be a useful means of plant protection. In this study we have reviewed our research on resistance imparted by antimicrobial bovine lactoferrin in transgenic plants against important fungal and bacterial pathogens. Transgenic plants exhibited moderate to high levels of resistance to soilborne plant pathogens. The use of the lactoferrin gene is a potential new approach to consider for control of diseases caused by plant pathogens.
Technical Abstract: Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein and it is known to exert a broad-spectrum primary defense activity against bacteria, fungi, protozoa and viruses in mammals. The Bovine lactoferrin gene was introduced to tobacco (Nicotiana tabacum var Xanthi), Arabidopsis (A. thaliana) and wheat (Triticum aestivum) plants via Agrobacterium. Detached leaves of transgenic tobacco plants exhibited high levels of resistance against a fungal pathogen Rhizoctonia solani. In addition, transgenic Arabidopsis seedlings were resistant to R. solani and did not exhibit damping off symptoms. Transgenic wheat showed a significant reduction of disease incidence caused by F. graminearum compared to control wheat plants. The level of resistance in the highly susceptible wheat cultivar Bobwhite was significantly higher in transgenic plants compared to control Bobwhite and to the untransformed commercial wheat cultivars, susceptible Wheaton and tolerant ND 2710. Quantification of the expressed lactoferrin protein by ELISA in transgenic wheat indicated a positive correlation between the lactoferrin gene expression levels and the levels of disease resistance. Previous studies have shown that LF also imparts resistance to plants against a bacterial pathogen Ralstonia solanacearum. This, together with the fact that LF is considered to be a safe food component, makes it a potentially highly desirable candidate to introduce broad spectrum resistance against plant pathogens.