• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.2
• /
• pp.159-165
• /
• 1993

To clarify the effects of sink demand for assimilate on leaf photosynthetic rate, tissue composition, and leaf senescence of soybean [Glycine max (L.) Merr.] J plants, pod and leaf tissues were removed at growth stage $R^3$. Plant responses were measured every 10days from 2 through 42days following treatment. Leaves of depodded plants exhibited increased starch and chlorophyll contents and specific leaf weight. Stomatal resistance was also increased and leaf photosynthetic rate was reduced. Dry weight of vegetative tissues except leaves was increased by pod removal. Leaf removal resulted in a decreased starch content of leaves from 22 to 42days after treatment and that of roots at all sampling times. Specific leaf weight was decreased while leaf photosynthetic rate was increased. Stomatal resistance and chlorophyll content were little affected. Weight per seed was decreased 3.0% by leaf removal. Except for the seed, tissue protein contents were increased by pod removal but decreased by leaf removal, however, seed protein content was not affected by either. Apparent senescence was delayed by depodding. Both apparent and functional senescence were accelerated by leaf removal.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.3
• /
• pp.281-288
• /
• 2007

Photoperiod sensitive genetic male sterile (PGMS) rice is sterile mutant controlled by photoperiod. A PGMS mutant 920S was sterile grown under long-day (LD) photoperiod (14 h light/10 h dark) but fertile grown under short-day (SD) photoperiod (10 h light/14 h dark). Proteome analysis revealed that 12 protein spots were differentially expressed in the spikelets of 920S plants either treated with LD or SD photoperiod. Among these proteins, three proteins including chlorophyll a/b binding protein, vacuolar ATPase ${\beta}-subunit,\;{\alpha}-tubulin$ and an unknown protein were more than three-fold abundant in the spikelet of the SD-treated plants than those of the LD-treated plants. On the other hand, eight proteins including acetyl transferase, 2, 3- biphosphoglycerate, aminopeptidase N, pyruvate decarboxylase, 60S acidic ribosomal protein and three unknown protein spots were more abundant in the spikelets of the LD-treated plants than those of the SD-treated plants. The results suggest that the observed proteins may be involved in sterile or fertile pollen development under LD or SD photoperiod respectively in the PGMS mutant rice.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.3
• /
• pp.248-255
• /
• 2010

This study was carried out to assess the feasibility of the electron beam irradiation as a mean of red tide control in coastal water. Prorocentrum minimum, Prorocentrum micans, Cochlodinium polykrikoides, Heterosigma akashiwo, Alexnadrium catenella were selected and cultured for experiments, and red tide occurring in Tongyeong(2007. 8. 15) was also tested under the same conditions. The irradiation dose were 1 kGy, 2 kGy, 4 kGy and 8 kGy. The result showed 50~65% extinction in red tide cells was observed right after irradiation dose of 1 kGy and 86~97% within 1 day after irradiation, compared with control. Chlorophyll-a concentration of red tide was reduced by 50~64% immediately and it was drastically reduced up to 86~97% 1 day after irradiation. When the culture was irradiated at 1 kGy, 28~47% of s-protein was released immediately, and 77~138% was released 1day after irradiation. 77~212% of s-carbohydrate was excreted after 1 day while 16~45% of s-carbohydrate was excreted immediately. A transmission electron microscope(TEM) observation for the irradiated red tide revealed that the cell was destroyed and intracellular biopolymeric substance was leached out from the damaged cell as a result of electron beam irradiation. These results imply that electron beam irradiation is enable to control red tide by flocculation with extracellular biopolymer. The paralytic shellfish poisoning(PSP) toxin contents produced by Alexandrium catenella was decreased 48% by 1 kGy of electron beam irradiation compared with the unirradiated cells. As a result, electron beam irradiation was effective for detoxication as well as destruction of red tide.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.1
• /
• pp.7-13
• /
• 2006

Plastichouse cultivation for crops and vegetables in the winter has been widely popularized in Korea. In the vinylhouse Ultraviolet B penetration is lower than in the field, and so some problems, as plant overgrowth and outbreak of disease, occurred frequently. The effect of artificial supplement ultraviolet B $(UV-B:280{\sim}320nm)$ radiation on the physiological responses and yield of perilla (perilla frutescens) was investigated UV-B ray was radiated on perilla with the 10th leaf stage at the distance of 90, 120 and 150 cm from the plant canopy for 30 days after planting in the vinylhouse. The production of fresh perilla leaves was high in the order of plastic house, ambient+50% of supplemental UV-B, ambient ambient+100% of supplemental UV-B. Enhanced UV-B radiation affected the intensity of thirty-three proteins in 2-dimensional electrophoretic analysis of proteins and ten proteins out of them seemed to be responsive to UV-B : a protein was, ATP synthase CF1 alpha chain, down regulated and nine proteins (Chlorophyll a/b bindng protein type I, Chlorophyll a/b binding protein type II precursor, Photosystem I P700 chlorophyll a apoprotein A2, DNA recombination and repair protein recF, Galactinol synthase, S-adenosyl-L-methionine, Heat shock protein 21, Calcium-dependent protein kinase(CDPK)-like, Catalase) were up-regulated.

• Journal of Life Science
• /
• v.18 no.12
• /
• pp.1705-1711
• /
• 2008

To investigate the relationship between cold stress and the activity of ascorbate peroxidase(APX), dehydroascorbate reductase (DHAR), mRNA expression level of two enzymes, hydrogen peroxide content was studied in lettuce leaves under stress condition imposed by cold stress at $4^{\circ}C$ for 24 hr in the dark and following recovery at $20^{\circ}C$ from cold stress. Hydrogen peroxide content increased gradually in lettuce leaves during cold stress, but decreased slightly following recovery from cold stress. Soluble protein content, however, decreased gradually during cold stress, and then rapidly returned to normal levels following recovery. Total chlorophyll content decreased gradually during cold stress, and then keep constant following recovery. The patterns of chlorophyll a and b content similar to that of total chlorophyll content, and carotenoid content didn't change. The ratio of chlorophyll a and total chlorophyll was increased during cold stress, but decreased with rapid during cold stress, and then the ratio returned to normal levels following recovery. During cold stress, the activity of APX and DHAR in the lettuce leaves increased dramatically, and also transcript levels of mRNA of APX and DHAR, as determined by probing 32P-labeled single stranded RNA of APX and DHAR, highly increased and returned to normal levels following recovery, respectively. Relationship between APX and DHAR activity and hydrogen peroxide highly related ($R^2$=0.8715 and 0.8643), whereas between hydrogen peroxide and total chlorophyll content and soluble content related reversely ($R^2$=0.5021 and 0.8915).

• Journal of Plant Biology
• /
• v.33 no.1
• /
• pp.25-30
• /
• 1990

Effects of dimethipin on the senescence of excised barley first leaves were investigated. Dimethipin markedly inhibited chlorophyll and protein loss and reduced peroxidase activity relevant to senescence phenomena in th excised leaves. Dimethipin decreased hydrogen peroxide content, later malondialdehyde content, and increased the activities of superoxide dismutase and catalase. The antisenescence effects of dimethipin may result from the stabilization of membrane structure through inhibiting the peroxidation of unsaturated lipid and the accumulation of free radicals during senescence.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2005.05a
• /
• pp.64-66
• /
• 2005

Photosynthetic microbes possess a wealth of photoactive proteins including chlorophyll-based pigments, phototropin-related blue light receptors, phytochromes, and cryptochromes. Surprisingly, recent genome sequencing projects discovered additional photoactive proteins, retinal-based rhodopsins, in cyanobacterial and algal genera. Most of these newly found rhodopsin genes and retinal synthase have not been expressed and their functions are unknown. Analysis of the Anabaena and Chlamyrhodopsin with retinal synthase revealed that they have sensory functions, which, based on our work with haloarchaeal rhodopsins, may use a variety of signaling mechanisms. Anabaena rhodopsin is believed to be sensory, shown to interact with a soluble transducer and the putative function is either chromatic adaptation or circadian rhythm. Chlamydomonas rhodopsins are involved in phototaxis and photophobic responses based on electrical measurements by RNAi experiment. In order to analyze the protein, we developed a sensory rhodopsin expression system in E. coli. The opsin in E. coil bound endogenous all-trans retinal to form a pigment and can be observed on the plate. Using this system we could identify retinal synthase in Anabaena PCC 7120. We conclude that Anabaena D475 dioxygenase functions as a retinal synthase to the Anabaena rhodopsin in the cell.

• The Plant Pathology Journal
• /
• v.23 no.4
• /
• pp.281-286
• /
• 2007

Interactions between viral proteins and host proteins are essential for virus replication. Especially, translation of viral genes completely depends on the host machinery. In potyviruses, interactions of genome-linked viral protein (VPg) with host translation factors including eIF4E, eIF(iso)4E, and poly(A)-binding protein (PABP) has previously been characterized. In this study, we investigated interactions between Soybean mosaic virus (SMV) viral proteins and host translation factors by yeast two-hybrid system. SMV VPg interacted with eIF4E, eIF(iso)4E, and PABP in yeast two-hybrid system, while SMV helper component proteinase (HC-pro) interacted with neither of those proteins. The interaction between SMV NIb and PABP was also detected. These results are consistent with those reported previously in other potyviruses. Interestingly, we found reproducible and specific interactions between SMV coat protein (CP) and PABP. Deletion analysis showed that the region of CP comprising amino acids 116 to 206 and the region of PABP comprising amino acids 520 to 580 are involved in CP/PABP interactions. Soybean library screening with SMV NIb by yeast two-hybrid assay also identified several soybean proteins including chlorophyll a/b binding preprotein, photo-system I-N subunit, ribulose 1,5-biphosphate carboxylase, ST-LSI protein, translation initiation factor 1, TIR-NBS type R protein, RNA binding protein, ubiquitin, and LRR protein kinase. Altogether, these results suggest that potyviral replicase may comprise a multi-protein complex with PABP, CP, and other host factors.

• Korean Journal of Plant Resources
• /
• v.31 no.5
• /
• pp.522-530
• /
• 2018

Brachypodium distachyon has been developed as a monocot model plant for temperate grasses and bioenergy crops. Although B. distachyon research is moving forward rapidly, the study of photoresponses has not been explored. To extend our knowledge of responses to light in monocots, we performed photoresponse analysis of B. distachyon using two inbred lines, Bd21 and Bd21-3. In this study, we first compared growing phenotypes between the two lines and investigated coleoptile and primary leaf growths under dark, far-red, red, and white light conditions. The results showed that the growth of the two lines were similar until tillering stage, but other developmental stages from heading to senescence were much delayed in Bd21-3, which resulted in increased height and tiller numbers. Under different light conditions, primary leaf lengths were kept increasing during the growth period, whereas the coleoptile extension was inhibited 4 to 7 days after growth depending on the light conditions applied. These results suggest that the responses to light in B. distachyon can be examined by measuring coleoptile lengths approximately 7 days after seedling growth. Moreover, we selected light-responsive genes known in Arabidopsis thaliana, such as chlorophyll A/B binding protein (CAB), light-harvesting chlorophyll binding protein (Lhcb) and chalcone synthase (CHS), and confirmed their light-induced gene expression in B. distachyon. Therefore, the present study suggests that the inhibition of coleoptile growth can be used as the parameter to analyze photoresponses in the monocot model plant, and also provide the reference genes whose expression is induced by far-red and red light treatment.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.2
• /
• pp.213-219
• /
• 2018

This study was performed to determine the optimal time of harvest for ramie leaves with the two varieties (Seocheon Seobang and Seoncheon Baekpi) by comparison of physiological activity and physicochemical characteristics. The crude protein, minerals, ascorbic acid, folate, chlorophyll, ACE inhibitory activity and AChE inhibitory activity were determined. The amount of crude protein in ramie leaf, which was collected in Seocheon-gun, Chungcheongnam-do, grew up steadily from early May to September. The content of calcium in was higher in Baekpi than in Seobang. Seobang displayed its highest value of 3,569.90 mg% in September, while Baekpi displayed its highest value of 3,163.84 mg% in October. Although, folate and vitamin C contents in the two varieties were slightly different, they were higher as the growth date grew in October. The highest value of chlorophyll content was observed in October, which was later in the vegetative state. ACE inhibitory activity and AChE inhibitory activity appeared to be higher in Baekpi than in Seobang. Between June and August, ACE inhibitory activity was highest in Baekpi variety.