• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.175-175
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• 2017

To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the acquired salt tolerance of adapted cells was memorized. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. Consistently, salt adapted cells contained more lignin in their cell walls compared to control cells. The results provide new insight into mechanisms of plant adaptation to saline stress as well as stress memory in metabolic level.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.152-152
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• 2017

Plants exposed to environmental stress for long durations often can adapt to stress conditions with improved tolerance. Moreover this acquired tolerance to stress can be retained even after reverting to destressed growth conditions, which is known to stress memory. In these adaptation and stress memory processes, epigenetic regulation, such as DNA methylation and histone modifications play a key role. Here, we showed that regenerated rice plants from embryogenic callus exposed to gradually increasing NaCl concentrations (up to 120 mM NaCl) acquired salt tolerance and their enhanced tolerance are inherited to subsequent generations. The rice plants (R0) regenerated from rice callus under saline conditions were transplanted into normal paddy field and R1 seeds were harvested. These R1 seeds displayed higher germination rate on MS medium containing 100mM NaCl than wild-type. The callus derived from R1 seeds showed better growth than control callus on high salinity medium. And the salt-adapted R1 plants exhibited higher chlorophyll contents and also higher $K^+/Na^+$ ratio than wild-type rice under saline conditions. The results indicated that rice plants successfully adapted to saline growth conditions during regeneration on high salt medium and moreover this acquired tolerance to salt stress was inherited subsequent generation.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.218-242
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• 2022

Background: Promising specific growth regulators are employed in the tissue cultures of various bamboo species. Specific natural hardening mixtures support the acclimatization and adaptation of bamboo under protected cultivation. Results: The growth regulators like 2, 4-Dichlorophenoxyacetic acid (2, 4-D), Naphthaleneacetic Acid (NAA), Thidiazuron (TDZ), 6-Benzylaminopurine (BAP), Kinetin, Gelrite, Benzyl Adenine (BA), Indole Butyric Acid (IBA), Coumarin, Putrescine, Gibberellic acid (GA₃), Indole Acetic Acid (IAA) has been widely used for callus induction, root regeneration and imposing plant regeneration in various species of bamboo such as Bambusa spp. and Dendrocalamus spp. Different combinations of growth regulators and phytohormones have been used for regenerating some of the major bamboo species. Natural hardening materials such as cocopeat, vermicompost, perlite, cow dung, farmyard manure, compost, soil, garden soil, and humus soil have been recommended for the acclimatization and adaptation of bamboo species. Standard combinations of growth regulators and hardening mixtures have imposed tissue culture, acclimatization, and adaptation in major bamboo species. Conclusions: Bamboo contributes to soil fertility improvement and stabilization of the environment. Bamboo species are also involved in managing the biogeochemical cycle and have immense potential for carbon sequestration and human use. This paper aims to review the various growth regulators, natural mixtures, and defined media involved in regenerating major bamboo species through in vitro propagation. In addition, the ecological benefits of safeguarding the environment are also briefly discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.698-704
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• 1998

This study was carried out to investigate the effects of diet of Korean safflower(Carthamus tinctorious L.) seed powder on bone tissue during the recovery of rib-fracture in rats. Male Sprague-Dawley rats of 10 weeks old, weighing 370$\pm$5g, were divided into two groups including the control group(C group, AIN-76 semipurified diet) and safflower seed group(S group, AIN-76 semipurified diet+10% safflower seed powder) and were fed experimental diets for 12 days after adaptation period. After this period, the 9th right rib was fractured surgically and sham-operation was also performed. Rats were fed with experimental diets for up to 30 more days after rib-fracture. The degree of bone repair was evaluated during the recovery period at the 8th, 11th, 16th, 21st, 30th days after the surgical operation by microscopic observation of the fractured rib tissue. In callus formation, the portion of hyaline cartilage was noticably higher in S group than C group. The intracatilagenous ossification was observed at the 8th day in S group, but at 11th day in C group. The intramembranous ossification in callus was widely found over the 8th day to the 11th day in S group, but it was shown over the 11th day to the 16th day in C group. Bone resorption was also occured more rapidly in S group as indicated by large numbers of osteoclasts observed. At the 30th day, most of trabecular bones were disappeared in S group, whereas still shwon in C group over wide ranges of fractured ribs. These results imply that the supplementation of Korean safflower seed powder influences in the recovery of bone fracture by accelerating the process of bone repair.