Novel bifunctional nucleases, OmBBD and AtBBD1, are involved in abscisic acid-mediated callose deposition in arabidopsis

Min Kyoung You, Hyun Young Shin, Young Jin Kim, Sung Han Ok, Sung Ki Cho, Ji Ung Jeung, Sang-Dong Yoo, Jeong Kook Kim, Jeong Sheop Shin

Research output: Contribution to journalArticle

13 Citations (Scopus)


Screening of the expressed sequence tag library of the wild rice species Oryza minuta revealed an unknown gene that was rapidly and strongly induced in response to attack by a rice fungal pathogen (Magnaporthe oryzae) and an insect (Nilaparvata lugens) and by wounding, abscisic acid (ABA), and methyl jasmonate treatments. Its recombinant protein was identified as a bifunctional nuclease with both RNase and DNase activities in vitro. This gene was designated OmBBD (for O. minuta bifunctional nuclease in basal defense response). Overexpression of OmBBD in an Arabidopsis (Arabidopsis thaliana) model system caused the constitutive expression of the PDF1.2, ABA1, and AtSAC1 genes, which are involved in priming ABA-mediated callose deposition. This activation of defense responses led to an increased resistance against Botrytis cinerea. atbbd1, the knockout mutant of the Arabidopsis ortholog AtBBD1, was susceptible to attack by B. cinerea and had deficient callose deposition. Overexpression of either OmBBD or AtBBD1 in atbbd1 plants complemented the susceptible phenotype of atbbd1 against B. cinerea as well as the deficiency of callose deposition. We suggest that OmBBD and AtBBD1 have a novel regulatory role in ABA-mediated callose deposition.

Original languageEnglish
Pages (from-to)1015-1029
Number of pages15
JournalPlant Physiology
Issue number2
Publication statusPublished - 2010 Feb 1


ASJC Scopus subject areas

  • Plant Science
  • Genetics
  • Physiology

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