The bean bug, Riptortus pedestris, is one of major hemipteran pests against the soybean, Glycine max in Korea. In previous study, it was suggested that water-taking in the first instar nymphal stage of R. pedestris is certainly necessary for successful ecdysis and their survival. To investigate water-taking behavior of the first instar nymphs of R. pedestris on plant, electrical penetration graphic patterns were analysed while R. pedestris fed on the napa cabbage leaf, Brassica rapa subsp. pekinensis by using EPG system. In the result, a X-waveform was dominantly observed for average 42.0 min out of total recording time (120 min). There was significant positive correlation (r = 0.457, P = 0.000452, n = 55) between body weight increase and cumulative durations of X-waveform. In addition, histological observation of cross-sections indicated that stylet tip in the plant tissue during X-waveform period is located nearby xylem cells, suggesting that X-waveform is closely related to xylem sap feeding behavior of R. pedestris in plant.

저온 조건하에서 추파 청예작물의 의한 질산태 질소 흡수 및 이용에 대한 대사기전을 규명하기 위해 호밀과 사초용 유채의 생육온도를 5 ∘ C 및 25 ∘ C 로 처리 후 뿌리를 양분하여 14 N 과 15 N 을 각각 공급하여 15 N 의 식물체내 이동을 추적하였다. 5 ∘ C 에서 9일간 호밀과 유채에 의해 흡수된 질산태 질소의 함량은 25 ∘ C 처리구에 비해 각각 59.3% 및 27.1%가 감소하였다. 25 ∘ C 조건하에서 9일간 호밀 및 유채에 있어 흡수된 질산태 질소의 약 2.5% 및 7.6%가 뿌리로 전이되었고, 5 ∘ C 조건하에서는 뿌리로 전이된 질산태 함량은 각각 3.8% 및 10.9%로 증가하였다. 목부를 통해 잎으로 전이된 질소의 함량은 25 ∘ C 조건하의 호밀 및 유채에서 개체당 각각 55.9 및 54.4 mg N이었으며, 5 ∘ C 에서는 각각 22.1 및 38.8 mg N으로 저온 처리에 의해 목부를 통한 전이된 질소 함량은 각각 60.4% 및 28.8%가 감소되었음을 보여 주었다. 호밀과 유채 공히 체관부를 통해 잎에서 뿌리로 전이된 질소의 함량은 다른 경로를 통한 질소 전이량에 비해 가장 낮았으며, 저온 처리에 따른 전이량의 변화폭 역시 가장 낮았다. 25 ∘ C 조건하에서 호밀 및 유채에 있어 총 흡수된 질소의 2.5% 및 0.5%이었으며, 5 ∘ C 조건하에서 이 비율은 각각 5.2% 및 0.9%로 증가하였다.

The vascular system of plants consists of two conducting tissues, xylem and phloem, which differentiate from procambium cells. Xylem serves as a transporting system for water and signaling molecules and is formed by sequential developmental processes, including cell division/expansion, secondary cell wall deposition, vacuole collapse, and programmed cell death (PCD). PCD during xylem differentiation is accomplished by degradation of cytoplasmic constituents, and it is required for the formation of hollow vessels, known as tracheary elements (TEs). Our recent study revealed that the small GTPase RabG3b acts as a regulator of TE differentiation through its autophagic activation. By using an Arabidopsis in vitro cell culture system, we showed that autophagy is activated during TE differentiation. Overexpression of a constitutively active RabG3b (RabG3bCA) significantly enhances both autophagy and TE differentiation, which are consistently suppressed in transgenic plants overexpressing a dominant negative form (RabG3bDN) or RabG3bRNAi (RabG3bRNAi), a brassinosteroidinsensitive mutant bri1-301, and an autophagy mutant atg5-1. Wood (called secondary xylem) is the most abundant biomass produced by land plants including Populus and Eucalyptus, and therefore is considered to be one of the most cost-effective and renewable bioenergy resources. In an attempt to enhance xylem differentiation and thus to improve biomass traits in poplars, we generated transgenic poplars overexpressing the RabG3bCA form. As notable phenotypes, both stem height and diameter were increased and xylem area in vascular bundles was significantly expanded in RabG3bCA transgenic poplars compared to control plants. Taken together, these results demonstrate that RabG3b regulates xylem differentiation in both Arabidopsis and Populus. This study enhances our understanding of biological mechanisms underlying wood formation and serve as a framework to engineer the quality and quantity of wood as useful biomass.

Brassinosteroids (BRs) play important roles in many aspects of plant growth and development. BR-induced AtBEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response in Arabidopsis. Here, we identified a poplar (Populus alba x P. glandulosa) BEE3 homolog encoding a putative basic helix-loop-helix (bHLH)-type transcription factor through microarray analysis. Transcripts of PagBEE3 were mainly detected in stems, with the internode having a low level of the transcripts and the node having a relatively higher level. The function of the PagBEE3 gene was investigated through the phenotypic analyses with PagBEE3-overexpressing (ox) transgenic lines. This work mainly focused on a potential role of PagBEE3 in stem growth and development of polar. The PagBEE3-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Microarray analysis revealed that the expression of many genes involved in xylem cell proliferation and development was altered in the PagBEE3-ox plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3-ox plants and PagBEE3 plays a role in the stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems.

An Arabidopsis small GTPase, RabG3b, was previously characterized as a component of autophagy and as a positive regulator for xylem development in Arabidopsis. In this work, we assessed whether RabG3b modulates xylem-associated traits in poplar in a similar way as in Arabidopsis. We generated transgenic poplars (Populus alba x P. tremula var. glandulosa) overexpressing a constitutively active form of RabG3b (RabG3bCA) and performed arrange of morphological, histochemical, and molecular analyses to examine xylogenesis. RabG3bCA transgenic poplars showed increased stem growth due to enhanced xylem development. Autophagic structures were observed in differentiating xyelm cells undergoing programmed cell death (PCD) in wild type poplar, and were more abundant in RabG3bCA transgenic poplar plants and cultured cells. Xylogenic activation was also accompanied by the expression of secondary wall-, PCD-, and autophagy-related genes. Collectively, our results suggest that Arabidopsis RabG3b functions to regulate xylem growth through the activation of autophagy during wood formation in Populus, as does the same in Arabidopsis.

우리나라에서 수액으로 채취하는 수종인 대나무, 참다래 나무, 고로쇠나무의 수액을 이용하여 메주에 천일염과 죽염을 섞어 재래식 제조방법으로 3개월 발효 숙성시킨 후 간장의 품질특성을 비교 분석하였다. pH는 천일염으로 제조한 참다래수액 간장이 높았으며, 색도는 일반물로 제조한 간장보다 수액으로 제조한 간장의 색도(명도)가 높았고, 식염과 아미노태질소 함량은 참다래수액 간장이 높게 나타났다. 수액종류에 따른 간장의 유기산 조성은 malic acid가