Charng-Pei Li, Dong-Hong Wu, Shou-Horng Huang, Menghsiao Meng, Hsien-Tzung Shih, Ming-Hsin Lai, Liang-Jwu Chen, Kshirod K Jena, Sherry Lou Hechanova, Ting-Jyun Ke, Tai-Yuan Chiu, Zong-Yuan Tsai, Guo-Kai Chen, Kuan-Chieh Tsai, Wei-Ming Leu

Int J Mol Sci.; 2023 Jan 16; 24(2):1798. doi: 10.3390/ijms24021798.

Abstract

Brown planthopper (BPH), a monophagous phloem feeder, consumes a large amount of photoassimilates in rice and causes wilting. A near-isogenic line ‘TNG71-Bph45’ was developed from the Oryza sativa japonica variety ‘Tainung 71 (TNG71) carrying a dominant BPH-resistance locus derived from Oryza nivara (IRGC 102165) near the centromere of chromosome 4. We compared the NIL (TNG71-Bph45) and the recurrent parent to explore how the Bph45 gene confers BPH resistance. We found that TNG71-Bph45 is less attractive to BPH at least partially because it produces less limonene. Chiral analysis revealed that the major form of limonene in both rice lines was the L-form. However, both L- and D-limonene attracted BPH when applied exogenously to TNG71-Bph45 rice. The transcript amounts of limonene synthase were significantly higher in TNG71 than in TNG71-Bph45 and were induced by BPH infestation only in the former. Introgression of the Bph45 gene into another japonica variety, Tainan 11, also resulted in a low limonene content. Moreover, several dominantly acting BPH resistance genes introduced into the BPH-sensitive IR24 line compromised its limonene-producing ability and concurrently decreased its attractiveness to BPH. These observations suggest that reducing limonene production may be a common resistance strategy against BPH in rice.

See https://pubmed.ncbi.nlm.nih.gov/36675314/

Figure 2

The settling preference of BPH examined using a Y-maze olfactometer. BPHs were released in a Y-maze tube with air supplied through containers containing 10 TNG71 or TNG71-Bph45 rice plants, which were (A) not previously invaded and (B) previously invaded by 300 BPHs for 3 days. The percentage of BPHs that moved to each side of the trap was calculated 2 days after release. Statistical analysis was performed using Student’s paired t-test (N = 4). * p < 0.05 and ** p < 0.01.