장미 속은 오랜 시간에 걸쳐 잡종화, 배수화 및 육종 등을 통해 약 250개의 종과 30,000여 품종이 존재하는 진화 역사를 가지고 있으며, 다양한 분류체계로 구분되고 있다. 이에, 본 연구 는 장미 속 자원의 다양성을 평가하고 자생식물 해당화의 육종적 활용을 위해 수행되었다. 장미 속 자원의 형태학적 다양성을 확인하기 위해 장미 속 자원 303점에 대해 형태적 특성조사를 실시하고 해당화 및 장미 속 자원 29점을 선발하여 SSR 분석을 실시하였다. 추가적으로, 해당화의 육종적 활용을 위한 자원 6점 을 선발하고 화분 검정을 실시하였다. 본 연구의 결과, 장미 속 자원 303점의 다양성 평가 결과에서 유사한 형태적 특징을 지닌 자원끼리 7개 그룹으로 나뉘었다. 선발된 29개 자원의 형태학적 데이터와 분자학적 데이터를 이용한 군집 분석 결과, 데이터의 유사성을 보인 자원끼리 각각 5개, 4개 그룹으로 구분되었다. 또한, 혼합분석 시에는 3개 그룹으로 확인되었다. 분류 결과를 바탕으로 자생 식물을 이용한 정원장미 육종을 위해 각각 특성이 다른 해당화를 3점 선발하였고 장미 속 자원에 속하는 정원 장미 3점을 선발하여 총 6자원을 선발하였다. 선발된 자원의 화분 검정 결과, 종간 교잡체를 제외한 5가지 자원에서 90% 이상의 정상화분율을 확인하였다. 본 결과는 자생식물 해당화를 재평가 하고 정원 장미 육종 전략 수립에 도움이 될 것으로 기대된다.

Toll and IMD pathways play an important role in producing antimicrobial peptides (AMPs) through NF-κB in insects. The functions of IκB kinase (IKK) complex regulating the NF-κB signaling cascade have not yet been investigated in Tenebrio model. Here, we identified TmIKK-β (or TmIrd5) which contains 2,112 bp encoding 703 amino acid residues. Domain analysis shows that TmIKK-β contains one Serine/Threonine protein kinases catalytic domain. Developmental expression patterns indicate that TmIKK- β gene was highly expressed in early pupal (P1) and adult (A5) stages. Tissue specific profiles show that TmIKK-β was highly expressed in the integuments in last instar larvae, and fat body and hemocytes in 5 day-old adults. TmIKK-β1 transcripts were strongly induced at 3 and 12 h-post injection of E. coli, and 3 h-post injection of S. aureus or C. albicans in hemocytes. In gut, TmIKK-β transcripts were slightly induced by E. coli (at 6, 9 and 24 h) and C. albicans (at 24 h), while it was not induced by S. aureus challenge. Moreover, it was highly induced at 6 h-post injection of E. coli and then it was gradually decreased in the fat body. To understand the immunological role of TmIKK-β, gene specific RNAi and mortality assay was performed. Depletion of TmIKK-β mRNA leads to increase microbial susceptibility of larvae against E. coli, S. aureus and C. albicans. In addition, induction patterns of fourteen AMP genes in response to microbial challenge was tissue specifically investigated in TmIKK-β–silenced T. molitor larvae. The results suggest that expression of ten AMP genes out of fourteen genes were drastically decreased by TmIKK-β RNAi in fat body, suggesting that TmIKK-β plays an important role in antimicrobial innate immune responses.

It has been well known that IKK-β, -ε and –γ play a pivotal role in IMD pathway. In this study, TmIKK-ε was identified and their functions in countering pathogenic infections were investigated. We identified TmIKK-ε gene which including 2,196 bp nucleotides (encoding 731 amino acid residues). Domain analysis of TmIKK-ε indicates that there is one Serine/Threonine protein kinases catalytic domain. TmIKK-ε gene was highly expressed in 2 day-old pupal stage and the expression was gradually decreased until 1 day-old adults. Then the expression was slightly increased until 4 day-old adult stage. Tissue specific expression of TmIKK-ε mRNA was high in the gut, integuments and hemocytes in last instar larvae, and fat body, Malpighian tubules and testis in 5-daysold adult. In hemocytes, TmIKK-ε was drastically induced by E. coli injection after 3 h and by S. aureus at 3 and 12 h-post injection. In gut, expression level of TmIKK-ε was high at 6 h-post injection of microbial injection. Expression of TmIKK-ε in fat body was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-ε, gene specific RNAi and mortality assay were performed. TmIKK-ε RNAi caused increased larval mortality against E. coli, not S. aureus and C. albicans. Finally, to investigate the induction patterns of Tenebrio fourteen AMP genes in response TmIKK-ε RNAi, three microorganisms were treated into TmIKK-ε-silenced T. molitor larvae. Nine out of fourteen AMP genes were not induced by microbial challenge in TmIKK-β dsRNA-injected group. Taken together, our results indicate that TmIKK-ε may regulates nine antimicrobial peptide genes in response to microbial challenge in T. molitor fat body.

IKK-γ is an essential protein to form IKK complex which regulate NF-κB. We identified TmIKK-γ (or TmKenny) gene which has 1,521 bp of nucleotides encoding 506 amino acid residues. Domain analysis of TmIKK-γ shows that there are one NF-κB essential modulator (NEMO) domain and a leucine zipper domain. Expression of TmIKK-γ gene was gradually increased from egg to 2-day-old pupal stage, dramatically decreased until 7 day-old pupal stage, and then it was gradually increased. TmIKK-γ transcripts were highly expressed in fat body and hemocytes in late instar larvae and integuments, fat body and Malpighian tubules in 5 day-old adult. TmIKK-γ was drastically induced by E. coli after 3 h challenges and by S. aureus at 3 and 12 h-post injection in hemocytes. TmIKK-γ was not induced by C. albicans although it was significantly induced by E. coli (at 3, 6 and 24 h) and S. aureus (at 9 h) in gut. In fat body, expression of TmIKK-γ was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-γ, gene specific RNAi and mortality assay was performed. larval mortality against microbial challenge was dramatically increased by TmIKK-γ RNAi. Furthermore, we investigate the tissue specific induction patterns of fourteen AMP genes in response TmIKK-γ dsRNA-treatment. In fat body, ten AMP genes out of fourteen was not significantly induced by microbial challenge in TmIKK-γ dsRNA-treated group. Based on these results, TmIKK-γ might play an important role in antimicrobial innate immune responses in Tenebrio molitor.