이번 연구에서는 white LED(420-680nm), blue LED(460- 490nm), green LED(520-550nm), red LED(620-650nm)를 포 함하는 서로 다른 빛의 파장을 가지는 light emitting diodes(LED) 가 포르피린 생합성과 항산화 기작에 미치는 영향을 조사하였다. 다양한 파장의 LED 광을 3일간 식물체에 조사하였을 때, white LED와 비교하여 blue LED로 처리된 애기장대 식물은 Mgprotoporphyrin IX (Mg-Proto IX), Mg-Proto IX methyl ester (ME), and protochlorophyllide을 포함하는 Mg-porphyrins을 현 저하게 증가시킨 반면에 red LED는 Mg-Proto IX과 Mg-Proto IX ME의 감소를 보여 주었다. 다양한 LED 중에서 blue LED가 white LED와 비교하여 CatA의 유전자 발현의 증가에 의해 표시 되는 항산화 작용의 증가를 크게 유도하였다. 또한, blue LED는 다 른 LED 광의 파장과 비교하여 애기장대의 anthocyanin 수준을 크 게 축적하였다. 이번 연구는 서로 다른 빛의 파장이 항산화 작용뿐 만 아니라 포르피린 생합성 과정을 변화시킴에 의해 식물의 생리학 적 특성에 큰 영향을 미침을 보여 준다.

The present study was conducted to determine plant growth and physiological responses of corn, barnyardgrass, and soybean to ALA (5-aminolevulinic acid). ALA effect on early seedling growth of test plants was greatly concentration dependant, suggesting that it inhibits at higher concentrations. No significant difference in herbicidal activity of two types of ALA on plant height and weight of test plants was observed. Barnyardgrass was the most sensitive to ALA and followed by corn and soybean, indicating that both crop plants were less affected by ALA concentration as well as different growth stages than barnyardgrass. Greatly reduced chlorophyll contents from leaves of three plant species were observed with increasing of ALA concentration. Compared with untreated controls, higher amounts of three tetrapyrroles were detected from three crop plants, indicating more accumulation in ALA-treated plants. The differential selectivity among plant species would be explained with the differences in tetrapyrrole accumulating capabilities, the susceptibility of various greening groups of plant species to the accumulation of various tetrapyrroles, and their metabolism in various plant tissues. The results indicate that negative biological potential of ALA exhibited differently on plant species, and that the photodynamic herbicidal activity against susceptible plants highly correlated with the extent of tetrapyrrole accumulation by the species.

Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase (Protox), the last shared enzyme of the porphyrin pathway in the expressed cytoplasm or the plastids, were compared with non-trangenic rice plants in their growth characteristics such as tiller number, plant height, biomass, and yield. Transgenic rice plants of ~textrmT3 generation had 8 to 15 % and 25 to 43% increases in tiller number compared to non-transgenic rice plants at 4 and 8 weeks after transplanting(WAT); similar values were observed for ~textrmT4 generation at 4 and 8 WAT. However, the plant height in both ~textrmT3 and ~textrmT4 generations was similar between transgenic rice plants and non-transgenic rice plants at 4 and 8 WAT. Transgenic rice plants had 13 to 32% increase in above-ground biomass and 9 to 28% increase in grain yield compared to non-transgenic rice plants, demonstrating that biomass and yield correlate with each other. The increased grain yield of the transgenic rice plants was closely associated with the increased panicle number per plant. The percent of filled grain, thousand grains and spikelet number per panicle were similar between transgenic and non-transgenic rice plants. Generally, the growth and yield of transgenic generations (~textrmT2 , ~textrmT3 , and ~textrmT4 ) and gene expressing sites (cytoplasm-expressed and plastid-targeted transgenic rice plants) were similar, although they slightly varied with generations as well as with gene expressing sites. The transgenic rice plants had promotive effects, indicating that regulation of the porphyrin pathway by expression of B. subtilis Protox in rice influences plant growth and yield.