• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.496-507
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• 2023

The in vitro organogenesis is one of important issues in plant embryology, and somaclonal variations are existing in calli and/or regenerants induced from a process of the organogenesis with in vitro circumstances. In this study, expressions of organogenesis-related genes were evaluated and genetic stability of regenerants derived from the process of in vitro organogenesis were measured using ISSR markers in Imperata cylindrica 'Rubra', Poaceae. The expressions of organogenesis-related genes were detected all of regenerants at the process of the organogenesis. All ISSR markers produced with an average of 71 bands per in vitro-cultured regenerants, and the scorable bands were varied from two to eight with an average of 5.14 bands per a primer. The polymorphism rates of the in vitro regenerants were higher than that of mother plants (1.4%), showing 4.1% (pot-cultured regenerants), 4.3% (field-cultured regenerants), 4.2% (in vitro-cultured regenerants), 5.6% (calli with green shoots) and 1.4% (calli), respectively. The genetic similarity matrix (GSM) among all accessions ranged from 0.747 to 1.0 with a mean of 0.868. GSM of the regenerants showed differences (from 0.972 to 1.00) compared with that of mother plants (0.991). According to the clustering analysis, two independent groups were divided into; the one is mother plants and regenerants cultured at room and open field, the other is regenerants cultured in vitro. The results give a new insight for understanding the dynamics of organogenesis in monocot plant.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.34-34
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• 2023

화본과 식물인 홍띠(Imperata cylindrica 'Rubra') 식물체의 기관분화 단계별 시료를 작성하여 이들 몇가지 기관분화에 관련된 유전자의 각 단계별 기관분화체에서 유전자존재와 발현여부를 조사하였다. 또한 식물의 기관분화에 관련된 유전자 정보를 얻기 위하여 일부 유전자의 특성을 정리하였다. 조사된 기관분화 관련 유전자중 탈분화 관련 유전자로는 FIF, RAP2-4 (WIND1) 유전자 등이, shoot 분화 관련 유전자로는 WUS, 부정근 분화관련 유전자로는 OsSCR, WOX11 등, 체세포배발생 관련 유전자로는 BBM1, SERK1, LEC1B, MEA 유전자 등이다. 이들 유전자중 RAP2-4(WID1), FIE, BBM1, SERK1, OsSCR, WOX11, WUS, LEC1B 유전자 등 8종의 기관분화 관련 유전자를 대상으로 화본과 식물의 기관분화의 각 단계별 기관분화체를 작성하여 PCR을 통하여 유전자(gDNA)의 존재여부를 확인한 결과 공시 유전자 모두 홍띠의 각단계 기관분화체에서 존재하였다. 또한 상기 유전자를 사용하여 화본과 식물의 각단계별 기관분화체에 대하여 유전자 발현을 확인한 결과 각단계 기관분화체에서 모두 발현하였다. 5종류 총 15개체의 기관분화 단계별 분화체에서 캘러스 발생 유전자인 FIE는 모식물체 1번을 제외한 14개의 식물체에서 모두 관찰되었으며, 뿌리 발생 유전자인 WOX11은 15개의 모든 식물체에서 탐색되었으며, 체세포 발생 유전자인 LEC1B는 15개 식물체에서 모두 발현하였으나 비교적 약하게 발현하였다. 이상과 같이 본 연구에서는 식물 기내발생시 기관분화관련 유전자의 동향을 파악하여 식물발생학의 기초자료를 구축하고자 하였다.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.300-306
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• 2022

The mitogen-activated protein kinase (MAPK) signaling cascade is essential for a wide range of cellular responses in plants, including defense responses, responses to abiotic stress, hormone signaling, and developmental processes. Recent investigations have shown that the stress, ethylene, and MAPK signaling pathways negatively affect the formation of nitrogen-fixing nodules by directly modulating the symbiotic signaling components. However, the molecular mechanisms underlying the defense responses mediated by MAPK signaling in the organogenesis of nitrogen-fixing nodules remain unclear. In the present study, I demonstrate that the Medicago truncatula mitogen-activated protein kinase kinase 5 (MtMKK5)-Medicago truncatula mitogen-activated protein kinase 3/6 (MtMPK3/6) signaling module, expressed specifically in the symbiotic nodules, promotes defense signaling, but not ethylene signaling pathways, thereby inhibiting nodule development in M. truncatula. U0126 treatment resulted in increased cell division in the nodule meristem zone due to the inhibition of MAPK signaling. The phosphorylated TEY motif in the activation domain of MtMPK3/6 was the target domain associated with specific interactions with MtMKK5. I have confirmed the physical interactions between M. truncatula nodule inception (MtNIN) and MtMPK3/6. In the presence of high expression levels of the defense-related genes FRK1 and WRKY29, MtMKK5a overexpression significantly enhanced the defense responses of Arabidopsis against Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Overall, my data show that the negative regulation of symbiotic nitrogen-fixing nodule organogenesis by defense signaling pathways is mediated by the MtMKK5-MtMPK3/6 module.