Abstract:

Oleocellosis, a widely distributed citrus disease, has a significant impact on the appearance and
commercial value of citrus fruits. To clarify the molecular mechanism of citrus oleocellosis, both forward and
reverse cDNA suppression subtractive hybridization libraries were constructed using RNA extracted from navel
oranges ‘Banfield’ with oleocellosis and healthy ones. Results showed that the length of majority of the inserts
ranged from 100 to 700 bp. A total of 292 clones were successfully sequenced from 300 randomly picked
positive clones, among which 165 ESTs in 55 genes were identified to share high homology with known genes
with E-value ＜ 1.0×10-3. GO and KEGG analysis showed that these differentially expressed genes (DEGs)
were mainly involved in redox stress, defense response, and biotic or abiotic stress. We therefore speculated that oxidative
stress might contribute to the formation of oleocellosis.

Key words: citrus oleocellosis, suppression subtractive hybridization (SSH), differentially expressed genes (DEGs), oxidative stress, real-time PCR