The control of the brown planthopper by the rice Bph14 gene is affected by nitrogen

Abstract

BACKGROUND: Brown rice planthopper (BPH) is a devastating rice pest in Asia. Bph14 is the first cloned BPH-resistance gene in rice, inducing callose deposition while impeding BPH feeding. Nitrogen application affects plant growth and resistance. However, there is little evidence on the influence of nitrogen on the callose content or regulation of rice BPH resistance. In this study, Luoyou9348 (containing Bph14 and highly resistant to BPH) and Yangliangyou6 (without Bph14 and susceptible to BPH) were planted under varying nitrogen regimes (0 , 90, 180 kg ha −1) to determine their effects on the resistance levels of rice to BPH feeding. The experiments involved BPH performance, plant volatile profiling and BPH preferences in laboratory and field experiments. RESULTS: We found that BPH egg hatching rate, total number of eggs laid and BPH preference increased with increasing nitrogen application in both rice varieties. However, the expression of Bph14, callose content and BPH feeding significantly declined with an increase in nitrogen fertilization in Luoyou9348, compared with Yangliangyou6. Also, the emission of volatile terpene compounds increased with increasing nitrogen application, which resulted in an increase in BPH numbers on both varieties. Two-way analysis of variance indicated a significant interaction between rice variety and nitrogen in BPH feeding behavior. CONCLUSION: Our findings provide an insight for addressing problems involved in the incorporation of insecticidal genes into crop plants. The effects of nitrogen on insecticidal gene expression in rice plant defense are discussed.

Volatile‐mediated tritrophic defense and priming in neighboring maize against Ostrinia furnacalis and Mythimna separata

“…Headspace volatiles were isolated and analyzed by gas chromatography-mass spectrometry (GC-MS) (QP-2010, Shimadzu, Shiga, Japan) with flame ionization detection as previously described. 43,48 N-hexane (1 mL) was used to elute volatiles from Super Q and prior to GC-MS analysis 10 μL of nonyl acetate (0.1 mg/mL; Sigma-Aldrich, St Louis, MO, USA) was added to each sample as an internal standard. Volatiles were identified by comparing their GC retention indices and MS spectra with data from the NIST11 library.…”

“…Ground leaf samples (50 mg each) were extracted and analyzed on a liquid chromatography-mass spectrometry (LC-MS) system (Xevo G2-XS Qtof) as previously described. 43,48,49 Four replicates were carried out per treatment.…”

“…The primed leaves were excised and then the JA and SA levels were determined as previously described. 43,48,49 Plants exposed to healthy plants were used as controls. For each treatment, four replicates were tested.…”

Integrative Transcriptomic and Proteomic Analysis Reveals an Alternative Molecular Network of Glutamine Synthetase 2 Corresponding to Nitrogen Deficiency in Rice (Oryza sativa L.)

“…Moreover, hybrid rice cultivation has significantly increased yield to feed the large population of China [4]. Honglian-type cytoplasmic sterility (CMS) is one of the three major CMS for three-line hybrid rice generation, and the hybrid rice variety LY9348 produced by Honglian-type male sterile line Longhong4A demonstrates remarkable agricultural characteristics, such as high yield, broad adaptability, disease resistance, insect resistance, high temperature tolerance, and high nitrogen use efficiency (NUE) [5,6]. Nitrogen (N), one of the essential nutrient elements for plant growth and yield [7,8], is not only a key component for building up many cell functional molecules, such as nucleic acid, ATP, amino acid, chlorophyll, and various plant hormones, but also a key regulator of many biological processes, including amino acid metabolism, carbon metabolism, and protein synthesis [9].…”

“…Moreover, hybrid rice cultivation has significantly increased yield to feed the large population of China [ 4 ]. Honglian-type cytoplasmic sterility (CMS) is one of the three major CMS for three-line hybrid rice generation, and the hybrid rice variety LY9348 produced by Honglian-type male sterile line Longhong4A demonstrates remarkable agricultural characteristics, such as high yield, broad adaptability, disease resistance, insect resistance, high temperature tolerance, and high nitrogen use efficiency (NUE) [ 5 , 6 ].…”