Interactions between Nitrogen and Silicon in Rice and Their Effects on Resistance toward the Brown PlanthopperNilaparvata lugens.
Nitrogen (N) and silicon (Si) are two important nutritional elements required for plant growth, and both impact host plant resistance toward insect herbivores. The interaction between the two elements may therefore play a significant role in determining host plant resistance. We investigated this interaction in rice (Oryza sativaL.) and its effect on resistance to the herbivore brown planthopperNilaparvata lugens(BPH). Our results indicate that high-level (5.76 mM) N fertilization reduced Si accumulation in rice leaves, and furthermore, this decrease was likely due to decreased expression of Si transportersOsLsi1andOsLsi2. Conversely, reduced N accumulation was observed at high N fertilization levels when Si was exogenously provided, and this was associated with down-regulation ofOsAMT1;1andOsGS1;1, which are involved in ammonium uptake and assimilation, respectively. Under lower N fertilization levels (0.72 and/or 1.44 mM), Si amendment resulted in increasedOsNRT1:1,OsGS2,OsFd-GOGAT,OsNADH-GOGAT2, andOsGDH2expression. Additionally, bioassays revealed that high N fertilization level significantly decreased rice resistance to BPH, and the opposite effect was observed when Si was provided. These results provide additional insight into the antagonistic interaction between Si and N accumulation in rice, and the effects on plant growth and susceptibility to herbivores.
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU)Guangzhou, China; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry UniversityFuzhou, China.
Xiaoying
X
Wu
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU) Guangzhou, China.
Yaoguang
Y
Yu
Natural Products Utilization Research Unit, United States Department of Agriculture - Agricultural Research Service, Starkville MS, USA.
Scott R
SR
Baerson
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU)Guangzhou, China; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry UniversityFuzhou, China.
Yuanyuan
Y
Song
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU) Guangzhou, China.
Guohua
G
Liang
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU) Guangzhou, China.
Chaohui
C
Ding
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Natural Resources and Environment, South China Agricultural University (SCAU) Guangzhou, China.
Jinbo
J
Niu
Natural Products Utilization Research Unit, United States Department of Agriculture - Agricultural Research Service, Starkville MS, USA.
Zhiqiang
Z
Pan
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University Fuzhou, China.
Rensen
R
Zeng
brown planthopper; growth–defense tradeoff; interaction; nitrogen; rice; silicon