title: Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes.
abstract: Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Tushar K
authors.initials: TK
authors.lastname: Dutta
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Papolu
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Prakash
authors.initials: P
authors.lastname: Banakar
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Choudhary
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Sirohi
authors.affiliation: Division of Nematology, ICAR-Indian Agricultural Research Institute New Delhi, India.
authors.forename: Uma
authors.initials: U
authors.lastname: Rao
keywords: Mi-cpl-1; RNAi; resistance; root-knot nematode; transgenics