Plant viral diseases are incurable and reduce fruit yield and quality, causing economic losses. Damages vary depending on the virus-host combination, virulence, and cultivar susceptibility. Therefore, the fundamental way to prevent virus damage is to cultivate virus-free plants. Thermotherapy, cold therapy, chemotherapy and cryotherapy combined with microshoot tip culture are used to eliminate fruit tree viruses. This review describes fruit viral diseases and summarizes the current elimination methods. Next-generation sequencing (NGS) has also been used to identify and diagnosis new fruit crop viruses. Therefore, studies are needed to optimize elimination methods for NGS-identified viruses.

복숭아 Y자 수형에서 기존 나무를 갱신할 때 고접갱 신을 통해 조기에 수형을 완성하고 생산성을 유지할 수 있는 방법을 알아보고자 수행한 연구결과는 아래와 같다. 접목위치별 활착률은 원가지 내측에 접목하는 것이 80% 로 외측의 73.3%에 비해 다소 양호하였고, 접목활착 후 발아된 신초의 기부직경은 내측이 36.2mm로 외측의 19.6mm에 비해 훨씬 굵게 자랐으며, 신초길이 역시 내측에 접목한 것이 220.3cm로 외측의 166cm에 비해 신초발육이 양호하였다. 고접갱신지는 개식수에 비해 수폭, 기부직경 및 결과지수 등에서 수체생장정도가 적은 것으로 나타났는데 수폭은 개식묘의 436.3cm에 비해 394.7cm 에 불과하였고, 수고는 고접위치를 감안하면 고접갱신지가 1m 정도 낮았다. 수형구성을 위한 노력시간은 고접 갱신지는 49.9시간/10a이었고, 개식묘는 51.5/10a로 두 처리 간 큰 차이를 보이지 않았지만, 고접갱신수의 경우 중간대목 품종의 관리시간 25.7시간/10a를 더하면 노력 시간이 더 소요되는 것으로 나타났다. 수형구성을 위한 노력요소 중 적심>유인>도장지 제거 순으로 많았다. 3년 간 누적수량은 처리 당년은 고접갱신수와 개식수 모두 생산량이 없었고 2년차는 고접갱신수의 생산량이 908kg/ 10a로 개식수 395kg/10a보다 훨씬 많았으나, 3년차에는 개식수의 수량이 고접수를 능가하였다. 그러나 고접수의 경우 중간대목 품종의 생산량을 합치면 개식수에서처럼 생산량의 공백 없이 매년 2,000kg 전후의 생산량을 유지할 수 있었다. 고접갱신 후 수량에 대한 손실보전을 위해 중간대목 품종을 3년에 걸쳐 연차적으로 갱신할 경우 과실수확을 위한 노동력, 과실봉지비, 농약비 및 수확, 선별 비용이 상대적으로 증가 되었지만, 수량증가와 더불어 개식에 따른 묘목비, 장비임대, 굴취비 및 지주시설 보수비용 등이 절감되어 매년 약 299만원/10a 정도의 소득적 이익이 발생하는 것으로 나타났다.

전엽 후 10일이 경과하면 잎의 위치별 엽내 엽록소 함량에 큰 차이를 보이지 않았고, 전엽 후 10일이 경과 되지 않은 잎의 엽록소 함량은 전엽 경과일수가 적을수록 낮았다. 동일한 잎의 위치에서 전엽 후 경과일수에 따른 엽록소 함량의 경시적 변화는 전엽 직후에 2.56μg/ cm2에서 12일째에는 6.35μg/cm2까지 급격히 증가하고 이후 약 2개월간 완만한 증가 추세를 보였는데 엽록소 함량이 가장 높은 시기는 전엽 후 11주째로 9.03μg/cm2 이었다. 엽면적은 전엽 직후부터 전엽 후 10일까지 급속하게 증가하였으나 그 이후는 거의 변화가 없었다. 잎의 광합성률은 전엽 후 30일까지는 급격히 증가하여 전엽 30일 후에 13.8μmol/m−2/sec−1로 최대치를 보였으며, 이후에는 잎의 광합성능이 급격하게 떨어졌다. 전엽 후 1 주와 4주의 광도에 따른 광합성률은 두 시기 모두 PPFD 600μmol/m−2/sec−1까지는 PPFD가 증가할수록 광합성률이 급격히 증가하였으나 이후 PPFD 1,200μmol/m−2/sec−1 까지는 완만한 증가율을 보이다 그 이상에서는 변화를 보이지 않았다. 전엽 후 1주와 전엽 후 4주간에는 전엽 후 4주가 전엽 후 1주에 비해 PPFD 증가에 따른 광합성률이 높은 경향을 보였다. CO2 농도별 광합성률은 600ppm까지는 농도가 높을수록 광합성성률이 증가하였으나 그 이상의 농도에서는 변화가 없었다. 차광시간별 엽내 sucrose 함량은 1시간 까지는 차광처리구와 무처리 구간 차이를 보이지 않았으나 2시간부터는 차광처리에서 sucrose 함량이 감소하였다.

본 연구에서는 GA 2.5% 도포제 처리가 자두 과실의 생리적 낙과 억제 및 과실 품질에 미치는 영향을 검토하였다. ‘포모사’ 과실에 대한 GA 도포제 처리는 과실의 생리적 낙과를 경감시켰으며 수정 후 처리시기가 빠를수록 생리적 낙과방지 효과가 높았다. ‘포모사’ 품종에 GA 도포제를 처리하고 착과율을 조사한 결과, 착과 율은 만개 후 3일 처리에서 61%, 만개 후 13일 처리에서 15%로 무처리 5%에 비해 현저히 높았다. GA 도포 제 처리구에서 착과율 증가는 ‘하니레드’, ‘추희’ 품종 에도 유사한 경향이었다. 또한, GA 도포제 처리는 과실의 비대 및 과실 성숙에 영향을 주었다. GA 도포제 처리구에서 ‘포모사’ 과실의 비대 양상을 조사한 결과, 만개 후 80일까지는 대조구와 유사하였으나, 만개 후 80일 이후에 대조구에 비해 과실 무게가 높게 나타났다. GA 처리된 ‘포모사’ 과실은 과중이 약간 높고, 당도, 산 함량 및 경도는 약간 낮은 것으로 나타났다. 그리고, ‘포모사’ 과실에서는 수확기 직전 즉 만개 후 85일경에 sucrose 함량이 증가하는데 GA 처리는 sucrose 함량 증가시기를 앞당겼다. 이를 종합하면, GA 도포제 처리는 자두에서 과실 생리적 낙과를 경감시켰으며 또한 과실의 성숙을 촉진하고 성숙기에 과실 비대를 촉진하였다.

Bone morphogenetic protein (BMP) 2 is a potent osteogenic factor. Although both Smad1/5 and mitogenactivated protein kinases (MAPKs) are activated by BMP2, the hierarchical relationship between them is unclear. In this study, we examined if BMP2-stimulated MAPK activation is regulated by Smad1/5 or vice versa. When C2C12 cells were treated with BMP2, the activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-N-terminal kinase was evident within 5 min. The knockdown of both Smad1 and Smad5 by small interfering RNA did not affect the activation of these MAPKs. In addition, neither the overexpression of Smad1 nor Smad5 induced ERK activation. When ERK activation was induced by constitutively active MEK1 expression, the protein level and activation of Smad1 increased. Furthermore, the inhibition of constitutively active BMP receptor type IB-induced ERK activation significantly suppressed Smad1 activation. These results indicate that Smad1/5 activation is not necessary for BMP2-induced MAPK activation and also that ERK positively regulates Smad1 activation.

Reparative dentine formation requires newly differentiated odontoblast-like cells. Therefore, identification of the molecule that stimulates the odontogenic differentiation of precursor cells in the tooth pulp will be helpful for the development of strategies to repair damaged pulp. In this study, we examined the effect of N-acetylcysteine (NAC) on the odontogenic differentiation of MDPC-23 cells, a mouse odontoblast-like cell line derived from dental papilla, and primary cultured rat dental papilla cells (RDPCs). NAC (1-30 mM) suppressed production of reactive oxygen species in MDPC-23 cells in a dose-dependent manner. Although 5 to 20 mM NAC did not alter MDPC-23 cell proliferation, 1 or 30 mM NAC significantly inhibited it. NAC enhanced mineralized nodule formation and the expression of several odontoblast differentiation-associated genes in both RDPCs and MDPC-23. This NAC stimulatory effect was significant, even at concentrations lower than 1 mM. However, NAC did not stimulate expression of bone morphogenetic protein-2, -4, or -7, which are known to enhance odontogenic differentiation. Since reactive oxygen species are also involved in the pulp toxicity of resin-based restorative materials, these results suggest that NAC may be a promising candidate for supplementation of dental restorative materials in order to enhance reparative dentine formation.

Tooth loss in elderly is mainly caused by alveolar bone loss via severe periodontitis. Although the severity of periodontitis is known to be affected by age, the aging process or the genetic changes during the aging of periodontal tissue cells are not well characterized. In this study, we investigated the effect of in vitro aging on the change of gene expression pattern in periodontal fibroblasts. Gingival fibroblasts (GF) and periodontal ligament fibroblasts (PDL) were obtained from two young patients and replicative senescence was induced by sequential subcultivation. When more than 90% cells were positively stained with senescence-associated β-galactosidase, those cells were regarded as aged cells. In aged GF and PDL, the level of phosphorylated retinoblastoma (RB) and p16INK4A protein was significantly decreased and increased, respectively. However, the protein level of p53 and p21, well known senescence-inducing genes, did not increase in aged GF and PDL. Although P27Kip1 and p15INK4B, another cyclin-dependent kinase inhibitors, were reported to be involved in replicative senescence of human cells, they were decreased in aged GF and PDL. Because senescent cells showed flattened and enlarged cell shape and are known to have increased focal adhesion, we examined the protein level of several integrins. Aged GF and PDL showed increased protein level of integrin α2, αu, and β1. When the gene expression profiles of actively proliferating young cells and aged cells were compared by cDNA microarray of 3,063 genes and were confirmed by reverse transcription-polymerase chain reaction, 7 genes and 15 genes were significantly and commonly increased and decreased, respectively, in aged GF and PDL. Among them, included are the genes that were known to be involved in the regulation of cell cycle, gene transcription, or integrin signaling. The change of gene expression pattern in GF and PDL was minimally similar to that of oral keratinocyte. These results suggest that p16INK4A/RB might be involved in replicative senescence of periodontal fibroblasts and the change of gene expression profile during aging process is cell type specific.

Calcium concentration in the bone resorption lacunae is high and is in the mM concentration range. Both osteoblast and osteoclast have calcium sensing receptor in the cell surface, suggesting the regulatory role of high extracellular calcium in bone metabolism. In vitro, high extracellular calcium stimulated osteoclastogenesis in coculture of mouse osteoblasts and bone marrow cells. Therefore we examined the genes that were commonly regulated by both high extracellular calcium and 1.25(OH)₂vitaminD₃(VD3) by using mouse oligo 11 K gene chip. In the presence of 10 mM [Ca²+]e or 10 nM VD3, mouse calvarial osteoblasts and bone marrow cells were co-cultured for 4 days when tartrate resistant acid phosphatase-positive multinucleated cells start to appear. Of 11,000 genes examined, the genes commonly regulated both by high extracellular calcium and by VD3 were as follows; 1) the expression of genes which were osteoclast differentiation markers or were associated with osteoclastogenesis were up-regulated both by high extracellular calcium and by VD3; trap, mmp9, car2, ctsk, ckb, atp6b2, tm7sf4, rab7, 2) several chemokine and chemokine receptor genes such as sdf1, scya2, scyb5, scya6, scya8, scya9, and ccr1 were up-regulated both by high extracellular calcium and by VD3, 3) the genes such as mmp1b, mmp3 and c3 which possibly stimulate bone resorption by osteoclast, were commonly up-regulated, 4) the gene such as c1q and msr2 which were related with macrophage function, were commonly down-regulated, 5) the genes which possibly stimulate osteoblast differentiation and/or mineralization of extracellular matrix, were commonly down-regulated; slc8a1, admr, plod2, lox, fosb, 6) the genes which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were commonly up-regulated; s100a4, npr3, mme, 7) the genes such as calponin 1 and tgfbi which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were up-regulated by high extracellular calcium but were down-regulated by VD3. These results suggest that in coculture condition, both high extracellular calcium and VD3 commonly induce osteoclastogenesis but suppress osteoblast differentiation/mineralization by regulating the expression of related genes.

The elderly suffer from an impaired immune function being obvious in a higher susceptibility to infections. Although the inflammatory cells are the major immunomodulatory cells, fibroblasts also secrete a variety of inflammatory cytokines and chemokines. Therefore periodontal tissue aging might playa role in development and progress of periodontitis. In this study, we investigated the effect of in vitro periodontal ligament cellular aging on the inflammatory cytokines, chemokines, and matrix metalloprotease(MMP)-2 expression induced by lipopolysaccharide(LPS) treatment. Three different cell populations were used; passages 4-5, 14-15, and 24-25 (at passage 27, more than 90% cells were replicative senescent). LPS increased the expression of interleukin(IL)-1β, IL-6, and tumor necrosis factor-α, IL-8, RANTES, and MMP-2. However, the order of induction folds were passages 14-15 > 4-5 > 24-25. While the expression level of Toll-like receptor(TLR) 4 decreased according to the increase in passage number, the level of TLR2 was highest at passages 14-15 and then decreased at passages 24-25. While the spontaneous expression of IL-8 decreased according to the increase in passage number, that of RANTES and proMMP-2 increased according to the increase in passage number. These results suggest that the aging of periodontal ligament fibroblasts differentially affect the role as immunomodulatory cells in response to periodontopathic bacteria and therefore might be another risk factor of periodontitis progression.

과피와 과육의 다양한 색은 복숭아 분류에 가장 널리 사용되는 상업적 기준 중 하나이다. 새로운 적색 과육 품종을 육성하기 위해서는 많은 교배 조합과 세대가 진전되어야 한다. 따라서 육종 효율을 높이기 위해서는 목적 형질을 가진 개체에 적용할 조기 선발 분자표지를 개발할 필요가 있다. 과육색이 다르게 발현되는 복숭아 품종의 유전자 발현을 비교하기 위해 2개의 cDNA library를 제작하였다. 적색 과육 품종인 ‘조생혈도’와 백색 과육 품종인 ‘미백도’의 유전자 발현 차이를 보기 위해 차세대 염기서열 분석(NGS) 기술을 사용하였고, 두 품종으로부터 얻은 EST의 염기서열을 결정하고 기존에 보고된 유전자와의 상동성을 분석하였다. ‘조생혈도’와 ‘미백도’의 EST database로부터 72쌍의 SNP 분자표지를 선발하였고, 적색 과육 품종 8개와 백색 과육 품종 24개를 구분할 수 있는 SNP 분자표지를 HRM 방법으로 분석하였다. 본 연구에서는 복숭아 EST database를 기반으로 HRM 분석 방법을 이용하여 복숭아 품종의 적육계와 백육계를 구분할 수 있는 효율적인 SNP 분자표지를 개발하였다. 이러한 SNP 분자표지는 복숭아 육종에 유용하게 사용할 수 있으며, 복숭아 품종의 다양한 색 변화에 관한 분자 기작 연구에 좋은 참고자료가 될 수 있을 것이다.

Apricot (Prunus armeniaca L.) cultivars show a gametophytic self-incompatibility (GSI) system, like other fruit species of Rosaceae family. Thus, it is necessary to determine their S-genotypes in order for stable fruit set in commercial cultivation. S-genotypes of apricots were determined by PCR and test crosses. Three sets of consensus primers designed from Prunus S-RNases were used to amplify fragments containing the first and second S-RNase intron, respectively. Through the results obtained from the 3 PCRs, we could identify SI genotypes of 33apricot cultivars. Several cultivars such as 'Heiwa', 'Yamagata No.3' and 'Shinsuoomi' had the self-compatible (Sc) allele. Self-pollination tests revealed that cultivars with Sc allele were self-compatible. Cross-pollination tests confirmed that there was cross-incompatibility between the cultivars with the same S-genotypes. These results might be very useful for growers for effective pollination and for breeders using these in cross breeding programs.