배 검은별무늬병(Venturia nashicola) 고도 저항성 ‘93-3-98’ 유래 PR-10 유전자의 특성

Characterization of PR-10 gene derived from highly resistant ‘93-3-98’ pear inoculated with scab (Venturia nashicola)

배 검은별무늬병 고도저항성 ‘93-3-98’과 고도감수성 ‘스위트스킨’간의 suppression subtractive hybridization 분석을 통해 ‘93-3-98’에서 특이적으로 발현되는 pathogenesis-related 10 (PR-10) 유전자를 분리하여 PyrcpPR-10으로 명명하고 기관 및 품종별 발현양상을 분석하였다. 단편염기서열의rapid amplification of cDNA ends PCR을 통해 PyrcpPR-10유전자는 전체길이가 743bp이고, 480bp의 ORF와 159개의 아미노산을 가지는 것으로 확인되었다. PyrcpPR-10 유전자의 염기서열은 ‘황실리’(저항성), ‘감천배’(중도저항성), ‘원황’(중도감수성), ‘신고’, ‘스위트스킨’(고도감수성)은 동일하였으나 ‘Bartlett’(고도저항성)은 일부 염기서열의 차이를 보였다. BLAST X를 통한 다른 식물 종의 PR-10 아미노산과 비교에서 64 ~ 98%의 상동성을 보였고 공통적으로 GXGGXG motif를 가지고 있었다. 기관 및 조직별 PyrcpPR-10 유전자의 발현량은 꽃잎이 가장 높았으며 다음으로 잎, 꽃대, 눈, 수피 순이었다. 저항성과 감수성 품종에 따른 PyrcpPR-10유전자의 발현양상은 모든 품종에서 접종 24시간 후 급격히 증가였으며, 특히 ‘Bartlett’, ‘93-3-98’, ‘황실리’에서 높게 발현되었고 ‘감천배’, ‘원황’의 경우 저항성 품종에 비해 상대적으로 낮았으며, 고도 감수성 ‘신고’, ‘스위트스킨’은 발현이 가장 낮았다. 배에서 분리한 PyrcpPR-10유전자는 검은별무늬병 저항성에 직접 연관되는 것으로 추정된다.

A PyrcpPR-10 gene with differentially expressed was isolated by using the suppression subtractive hybridization assay between ‘93-3-98’ (highly resistant against scab caused by Venturia nashicola) and ‘Sweat Skin’(highly susceptible) and analyzed the expression pattern according to organs and cultivars. The full length of PyrcpPR-10 was cloned as 743bp with 480bp’s ORP, and was determined to encode a protein of 159 amino acid residues. On analyzing PyrcpPR-10 gene sequence compared with resistant and susceptible cultivars, ‘Hwangsilri’ (resistant), ‘Gamcheonbae’ (moderately resistant), ‘Wonhwang’ (moderately susceptible), ‘Niitaka’ (highly susceptible), and ‘Sweat Skin’ (highly susceptible) had identical gene sequence but ‘Bartlett’ (highly resistant) showed partly different sequences. The deduced amino acid sequence showed 64 ~ 98% homology and had the GXGGXG motif to known amino acid of other plants PR-10 by the BLAST X analysis. Among several organs or tissues, petal was showed highest expression level of PyrcpPR-10 gene followed by leaf, floral axis, bud, and bark. The expression level of PyrcpPR-10 gene was dramatically increased at 24 hr after inoculation in all cultivars and also up-regulated in accordance with resistant degree of cultivars. While resistant cultivars (‘Bartlett’, ‘93-3-98’, and ‘Hwangsilri’) induced relatively high expression level of PyrcpPR-10 gene, susceptible cultivars (‘Niitaka’, and ‘Sweat Skin’) showed low expression level. PyrcpPR-10 gene is assumed that it is directly connected with defense mechanisms to pear scab.