현재 인간이 일반적으로 이용하는 의료용 단백질은 대개 동물세포 배양기술에 의하여 생산되고 있다. 그러나 제한된 특정 시설에서 생산되기 때문에 생산 단가가 높아서 전세계의 수요가 증가함에도 불구하고 일반화하는 데는 한계가 있는 실정이다. 이러한 문제를 극복하기 위하여 오래전부터 식물시스템을 이용하여 의료용 단백질을 생산하는 연구가 관심을 끌고 있다. 즉 쉽게 규모화할 수 있고 생산비용 효과도 경제적이고 동물세포보다 더 안전하게 의료용 단백질 생산할 수 있는 수단이 될 수 있기 때문이다. 이를 위하여 식물에 안정적으로 유전자를 핵 게놈과 엽록체 게놈에 형질전환 시키는 기술과 바이러스 운반체를 이용하여 일시적 발현을 유도함으로 의료용 단백질을 생산하는 기술이 개발되고 있다. 최근 해체 바이러스 기반의 운반체 개발은 재조합 단백질을 빠르고 일시적 발현으로 대량생산을 가능하게 하고 있다. 따라서 이 바이러스 발현시스템이 적절한 식물기반의 대량생산을 위한 플렛폼을 제공하고 있다. 따라서 본 총설은 식물로부터 의료용 단백질을 생산하는데 있어서 식물 바이러스발현 시스템 개발 및 이용에 대하여 기술하였다.

Acyl-acyl carrier protein (ACP) thioesterase (TE) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. A full-length cDNA of an acyl-ACP thioesterase, named CvFatB, was isolated from oil plant Cuphea viscosissima accumulating up to 90% caprylate (8:0) and caprate (10:0) in its seed oil. This cDNA contains a 1,245-bp open reading frame that encodes a protein of 415 amino acids. The deduced sequence also contains two essential residues (H317 and C352) for TE catalytic activity and a putative chloroplast transit peptide at the N-terminal. Overexpression of the CvFatB cDNA in Arabidopsis resulted in increased levels of saturated fatty acid, especially palmitate, and reduced levels of unsaturated fatty acids. The findings suggest that CvFatB from oil plant C. viscosissima can function as a saturated acyl-ACP TE and can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids.

The influences of ethylene inhibitors (AgNO3 and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of 50 μM Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate (AgNO3). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of 8-10 μM was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with 50 μM STS + 8 μM TDZ. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with AgNO3. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.