TITLE:
Loss of Resistance to Nilaparvata lugens May Be Due to the Low-Level Expression of BPH32 in Rice Panicles at the Heading Stage
AUTHORS:
Jirapong Jairin, Phikul Leelagud, Thida Saejueng, Varapong Chamarerk
KEYWORDS:
Rice, Brown Planthopper, Gene Expression, Heading Stage, BPH32
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.11,
October
27,
2017
ABSTRACT: The brown planthopper (BPH), Nilaparvata lugens (Stål), is the most important insect pest of rice
in Asia. Host plant resistance is one of the strategies currently used to
control BPH. The resistant rice cultivar Rathu Heenati (RH) carrying the BPH3 gene (recently renamed as “BPH32”)
remains effective despite more than 30 years of deployment. RH has been
determined to be resistant against BPH at all growth stages. However, we observed
that BPH could feed on panicles but not on the leaf sheaths of RH. The
resistance gene BPH32 was introduced into KDML105 through marker-assisted selection, and the
introgression line UBN03078 was developed. This rice line was used to observe
the patterns of target gene’s regulation. A low-level expression of BPH32 on panicles has been hypothesized to cause susceptibility in UBN03078 at the
heading stage. Findings from our gene expression analysis support the
hypothesis that the resistance gene was down regulated in the uppermost internodes compared with the leaf sheaths of
the heading rice plant. This phenomenon may allow BPH to feed on the panicles
of the resistant plants, but this requires further investigation.