title: Gene expression and plant hormone levels in two contrasting rice genotypes responding to brown planthopper infestation.
abstract: The brown planthopper (BPH; Nilaparvata lugens Stål) is a destructive piercing-sucking insect pest of rice. The plant hormones salicylic acid (SA) and jasmonic acid (JA) play important roles in plant-pest interactions. Many isolated rice genes that modulate BPH resistance are involved in the metabolism or signaling pathways of SA, JA and ethylene. 'Rathu Heenati' (RH) is a rice cultivar with a high-level, broad-spectrum resistance to all BPH biotypes. Here, RH was used as the research material, while a BPH-susceptible rice cultivar 'Taichung Native 1' (TN1) was the control. A cDNA microarray analysis illuminated the resistance response at the genome level of RH under BPH infestation. The levels of SA and JA in RH and TN1 seedlings after BPH infestation were also determined.
  
  
  
  The expression pattern clustering indicated that 1467 differential probe sets may be associated with constitutive resistance and 67 with the BPH infestation-responsive resistance of RH. A Venn diagram analysis revealed 192 RH-specific and BPH-inducible probe sets. Finally, 23 BPH resistance-related gene candidates were selected based on the expression pattern clustering and Venn diagram analysis. In RH, the SA content significantly increased and the JA content significantly decreased after BPH infestation, with the former occurring prior to the latter. In RH, the differential genes in the SA pathway were synthesis-related and were up-regulated after BPH infestation. The differential genes in the JA pathway were also up-regulated. They were jasmonate ZIM-domain transcription factors, which are important negative regulators of the JA pathway. Comparatively, genes involved in the ET pathway were less affected by a BPH infestation in RH. DNA sequence analysis revealed that most BPH infestation-inducible genes may be regulated by the genetic background in a trans-acting manner, instead of by their promoters.
  
  
  
  We profiled the analysis of the global gene expression in RH and TN1 under BPH infestation, together with changes in the SA and JA levels. SA plays a leading role in the resistance response of rice to BPH. Our results will aid in understanding the molecular basis of RH's BPH resistance and facilitate the identification of new resistance-related genes for breeding BPH-resistant rice varieties.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Changyan
authors.initials: C
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Luo
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Zaihui
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Ling
authors.affiliation: Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha, 410128, China.
authors.forename: Langtao
authors.initials: L
authors.lastname: Xiao
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Lin
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China. hchen@mail.hzau.edu.cn.
authors.forename: Hao
authors.identifier: 0000-0001-7654-5910
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism*; D063990:Gene Ontology; D017343:Genes, Plant; D018745:Genome, Plant; D005838:Genotype; D006430:Hemiptera / Q000502:physiology*; D012275:Oryza / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000469:parasitology*; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000469:parasitology; D010937:Plant Growth Regulators / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; D020156:Salicylic Acid
keywords: Insect-resistance; Nilaparvata lugens; Oryza sativa; cDNA microarray