Identify specific small RNA biomarkers and master regulators of citrus natural defense responses against HLB
C. HUANG (1), D. Niu (2) (1) UCR Plant Pathology and Microbiology Department, U.S.A.; (2) UCR Plant Pathology and Microbiology Department, U.S.A.

Huanglongbing (HLB) currently is the most devastating citrus disease and cause significant reduction of citrus quality and quantity, that seriously impacting the viability of citrus industry. Until now, no efficient disease control methods be identified due to poor understanding of pathogenesis and host responses. Host small RNAs (sRNAs) rapidly and specifically responded to pathogens, are one of the most attractive early diagnosis tool. sRNAs also play important roles on gene expression reprogramming in defense response. We took this advantage and developed early diagnosis biomarkers for HLB, as well as Citrus tristeza virus (CTV), a common disease of citrus. We have developed miR399 as early detection maker by compared sRNA expression profiles with HLB infected sweet orange and which also led to the phosphorous deficient symptom. We have tested with HLB infected trees from field and greenhouse in Florida, Texas, and southern California with different inoculation methods and resulted in good sensitivity and accuracy. We further investigated HLB susceptible and tolerant cultivars with HLB or CTV infection to identify:1) high accuracy of early diagnostic markers specific to HLB; 2) host natural defense responses and important master regulators for plant defense. Here we identified a panel of sRNAs for HLB early diagnosis. We also found sRNAs response to phosphorus deficient is behaved differently between HLB tolerant cultivar, US-942, and susceptible cultivars.

Abstract Number: P18-675
Session Type: Poster