Expression changes of stress-induced peroxidase (swpa2 and swpa4) and storage root-specific sporamin (spo-A and spo-B) genes were examined using qRT-PCR after treatment with wounding and bacterial pathogens on leaves of sweetpotato (Ipomoea batatas) plants. As a result of examining the expression change in the wounding treatment condition for 48 hours after treatment, which is a representative physical stress, the expression of all genes increased after 12 hours of wounding treatment, but the expression pattern of each gene group showed distinct differences thereafter. Expression levels of swpa2 and swpa4 strongly increased up to 36 or 48 hours after wounding treatment, whereas spo-A and spo-B expression levels strongly decreased after 24 or 36 hours after wounding treatment. Peroxidase and sporamin genes are involved in the early response after wounding treatment and, in particular, the peroxidase swpa2 and swpa4 genes are also involved in the late response after wounding treatment. Gene expression analysis after infection with P. chrysanthemi, which causes softness in sweetpotato, showed that the swpa2 and swpa4 genes were weakly induced after 8 hours and then strongly induced after 20 hours during pathogen infection. Expression of the spo-A gene was weakly induced in the pathogen-treated group after 20 hours, whereas spo-B showed an expression pattern similar to that of the peroxidase genes. The above results indicate that expression of the stress-induced peroxidase gene used in this study is induced not only by abiotic stress but also by biological stress caused by bacterial pathogen invasion and that peroxidase plays an important function in the initial defense response.

본 연구에서는 국내에서 식용으로 재배되고 있는 팽이버섯의 균사체에 대하여 Agrobacterium을 이용한 형질전환을 시도하였다. 특히 물리적 연마제인 미세 aluminum oxide 입자를 팽이 균사체 와 함께 강하게 교반함으로써 물리적 상해를 지니는 균사체를 제조하였으며 감압침윤에 의한 Agrobacterium 이용 형질전환을 시도하였다. Hygromycin 저항성을 이용한 선발 결과, 대조군에 서는 균사체 생육이 전혀 관찰되지 않은 반면 물리적 상해군에서는 형질전환균사체 생육이 확인되 었다. Genomic DNA PCR에 의한 유전자 도입을 확인함으로써 팽이균사체에 대한 매우 간편한 형 질전환법을 제시할 수 있었다.

단자엽 식물인 보리는 Agrobacterium을 이용한 형질 전환이 비교적 까다로운 편이다. 본 연구에서는 큰알1호, 내쌀보리, 올보리, 새찰쌀보리, 서둔찰보리,풍산찰쌀보 리의 유묘에 알칼리, 산화제, 환원제 등을 처리하여 화학 적 상처를 유발하였으며 이들에 감압진공을 이용한 Agrobacterium 형질전환을 실시한 후 GUS 유전자발현 을 분석하였다. 그 결과, 보리묘 생육을 일부 저하시킬 수 있는 농도의 화학물질 처리는 각기 다른 보리 품종의 형질전환율을 전반적으로 증대시킬 수 있는 것으로 판단 되었다. 화학물 중에서는 특히 hydrogen peroxide 처리 가 비교적 우수한 것으로 나타났다.

We carried out the effect of Si levels (0.5, 1.0 and 2.0 mM) on ethylene and salicylic acid (SA) of hydroponically grown rice plants, after 6h, 12h and 24h of Si application. All samples were analyzed after applying wound stress for 30 minutes. In 6 h treatments, 0.5 and 1.0 mM of Si decreased ethylene production by 7% and 9.9% respectively, while elevated level of Si (2 mM) insignificantly affected ethylene production under same conditions. However 0.5 and 1 mM of Si enhanced endogenous SA contents by 2.6% and 17.3% respectively, while 2 mM of Si decreased SA contents by 3% as compared to control. Samples analyzed after 12h of 0.5, 1 mM and 2 mM Si application showed reduction of 11%, 4% and 1.7% respectively, while SA contents increased by 4% and 9.5% in 0.5 and 1 mM Si treatments. Samples analyzed after 24 h of Si treatment showed that 0.5 and 1.0 mM of Si inhibited ethylene production by 12.6% and 18.2% respectively, while 2 mM Si increased ethylene production by 11.9% as compared to control. It was observed that the SA content of rice was almost similar to control in 0.5 mM Si applied treatments, while 1 mM and 2 mM of Si increased SA contents by 6.5% and 6.9% as compared to control. It was concluded that Si alleviates the effect of wounding stress in rice by regulating ethylene and SA production.

Agrobacterium-mediated genetic transformation of Brassica juncea cultivars has been extensively performed for the purpose of molecular breeding. B. juncea L. Czern var. Laciniata Makino, a vegetable crop also called kyona, can be transformed using its hyp

The effects of wounding and jasmonic acid(JA) on polyphenol oxidase(PPO) in tomato(Lycopersicon esculentum Mill.) seedlings were investigated. PPO was strongly induced by wounding or JA, and the response was also shown to be systemically induced by wounding. Mechanical wounding in cotyledon or leaf produced a signal that caused the concentration of PPO to increase in the unwounded cotyledon, in the first leaves but not in the second leaves. Severity of wounding and light intensity also affected wound induced change in PPO activity, JA showed a stimulatory effect on the loss of chlorophyll and the rapid increase in PPO activity. The PPO was clearly more active in the wounded leaves than in controls. The potency and specificity of the JA indicate a close relationship between JA and wound-induced changes in PPO in tomato species. JA and abscisic acid(ABA) acted similarly on both unwounded and wounded leaves, but the amount of PPO in the wounded leaves was always more than the respective controls. The highest increase in PPO activity occurred in woundand JA-induced leaves of seedlings kept under bright lighting. Benzyladenine(BA) completely abolished JA- and ABA-induced PPO activity. The results suggest that JA-induced PPO activity is due to de novo PPO synthesis. Histochemical tests for PPO in stems of wound- and JA-treated tomato plants indicate that PPO was localized primarily in the outer cortex and xylem parenchyma. It is concluded that exogenously applied JA acts as stress agents and PPO may be a component of the inducible anti-hervivore defense response.