J Integr Plant Biol. ›› 2006, Vol. 48 ›› Issue (12): 1458-1465.DOI: 10.1111/j.1744-7909.2006.00354.x

• Research Articles •     Next Articles

Functional Characterization of Mi, a Root-knot Nematode Resistance Gene from Tomato (Lycopersicon esculentum L.)

Ru-Gang Chen, Li-Ying Zhang, Jun-Hong Zhang, Wei Zhang, Xue Wang,Bo Ouyang, Han-Xia Li and Zhi-Biao Ye   

Abstract: Root-knot nematodes (Meloidogyne spp.) cause major economic damage to numerous crop species around the world. Plant resistance is the most important attribute that is able to suppress invasion by the root-knot nematodes. In the present study, a candidate root-knot nematode resistance gene (Mi) was isolated from the resistant tomato (Lycopersicon esculentum L.) line RN-1. Expression profiling analysis revealed that this gene was expressed specifically in the roots, stems, and leaves, but not in the flowers or fruits. To verify the real function of this candidate gene, both sense and inteference RNA (RNAi) vectors were constructed. We obtained 31 transgenic plants with between one and seven copies of T-DNA inserts of sense Mi from two nematode-susceptible tomato cultivars as assayed by polymerase chain reaction (PCR) and Southern blotting analysis. Reverse transcription-PCR analysis revealed that expression levels of the Mi gene varied in different transgenic plants. Nematode assays showed that the resistance to root-knot nematodes was significantly improved in some transgenic lines compared with untransformed susceptible controls and that the resistance was heritable in selfed progeny. Loss of function via RNAi further confirmed the role of the Mi gene and the original resistant lines became susceptible to root-knot nematodes.(Author for correspondence. Tel: +86 (0)27 8728 6867; Fax: +86 (0)27 8728 0016; E-mail zbye@mail.hzau.edu.cn)

Key words: Mi gene, overexpression, RNAi, root-knot nematode, tomato.

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q