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Harn, Chee Hark,Daie, Jaleh,Liu, Jang Ryol 한국식물학회 1997 Journal of Plant Biology Vol.40 No.4
A mechanism of coarse control of cytosolic FBPase under water stress has been investigated. Sugar beet plants grown in a green house were subjected to two different levels of water stress by withholding water: mild stress for 4 days and severe stress for 8 days. At mild stress, levels of transcript and protein in the leaves holding the water potential of -1.8 MPa were stable while the activity declined to 74% of control. At severe stress, the water potential in the leaves was approximately -4.0 MPa. The levels of the transcript and protein were 17% and 15% of the levels of control, respectively, suggesting the cytosolic FBPase gene was not expressed continuously in severe stress. However, the activity was still present although it is low (33% of control). Two dimensional protein gel was performed to find changes in the amino acid residues by charge modification under water stress. The isoelectric pH for the cytosolic FBPase on the Western blot was 5.4 at 37 kDa. The identical spot was found in different water stress levels indicating that protein modification of the cytosolic FBPase does not occur. Collectively, the regulation of cytosolic FBPase activity under water stress does not depend on the protein modification but depends on the biochemical levels at mild stress and the protein levels at severe stress.
Current Status of Seed Industry and Crop Breeding Strategies
Chee-Hark Harn 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07
Crop produce comes from seeds. It is important to have elite seeds for cultivation and harvesting. There are two major types of seeds in the seed market: F1 hybrid seeds and open-pollinated seeds (OP, traditionally pollinated). Farmers in developed countries plant F1 hybrid in most cases, while farmers in developing countries plant mainly OP. In fact, 60-70% of seeds planted in India and China are OP because OP is significantly cheaper. There are several reasons why the seed industry is important. First is for global food security. Based on the fact that the global population continues to increase steadily, additional productivity of 70% will be required to feed the global population by the year 2050. Second, seeds were traditionally used as food, both fresh and feed, but have now become materials for future industries of medicine, pharmaceutics, functional foods, energy, and may other applications. Third, new breeding programs based on biotechnology have changed the seed market dramatically. These programs are highly competitive and indeed play a major role, not only in the reduction of breeding time, the development of various genetic sources, the enhancement of purity and cost-saving, but also for the selection of value-added varieties. In Korea, F1 breeding began 65 years ago and the breeding programs for several vegetables and rice are in the top class worldwide. In addition, for the first time in 1999, a private seed company in Korea employed biotechnology for the purpose of crop breeding to develop platform technologies that could be utilized in the breeding practice. The major achievement so far is the development of DNA markers associated with resistance to disease, tolerance to the environment, and functional aspects. The application of genotyping has made many services possible, such as the purity control of F1 and inbred lines, variety verification, MAS (marker assisted selection), and MAB (marker assisted backcrossing). In addition, cell fusion and DH technologies have helped breeders to solve breeding limitations. There have been many cases of successful crop transformations, however, no GM varieties have been successfully commercialized in Korea. I bet this is inevitable, though. And it should be, because Korea imports lots of GM products, equivalent to $3 billion every year. More seed production and higher crop quality require new R&D strategies for breeding practices in the seed industry. Thanks to genomics information with big data and anti-GMO policies, new technologies are on the horizon, including genomic breeding, genome editing, in silico breeding and NBT (new plant breeding technology). I am going to talk more about the direction and strategy of R&D for crop breeding.
Development of Transgenic Peppers Tolerant to Disease and A Roadmap towards Commercialization
Chee Hark Harn 한국작물학회 2007 한국작물학회 학술발표대회 논문집 Vol.2007 No.11
The virus infection to pepper crops has caused a heavy loss in productivity. In Korea, CMV (cucumber mosaic virus) is the most frequent occurrence virus followed by PepMoV (pepper mottle virus) and TSWV (tomato spotted wilt virus). The total occurrence of pepper infection from these viruses is over 80%. Therefore, if we could develop a pepper variety tolerant to these viruses, then we would protect a large portion of pepper cultivation and production from the virus damage. In order to develop tolerant peppers against these viruses, we have set up a transformation system of pepper using Agrobacterium with viral genes such as CP (coat protein) gene and HC-Pro (helper component-protease) gene. Genes used for constructing transgenic peppers are CMVP0-CP, CMVP1-CP, PepMoV-CP, CMV-CP::PepMoV-CP, PepMoV-HC-pro-C/Ri, TSWV-CP and so on. A large number of transgenic peppers transformed with those genes was tested for resistance to viral pathogens. We have found that CMVP0-CP, CMVP1-CP peppers were tolerant to a new CMVP1 pathogen and finally T3 peppers highly tolerant to CMVP1 pathogen were selected. The selected T3 peppers were tolerant under field test. In addition, transformed peppers highly tolerant to PepMoV were also selected. Here in Korea, none of the GM crops has ever been approved for safety testing yet. Although researchers in universities and national institutes have developed tens of GM crops during the last 10 years or so, only a few crops have been recently tested for the risk assessment. Unfortunately, it will take several years until any GM crops are on the Korean market. In other words, the present status of GM crop development in Korea is far behind worldwide levels in terms of research and development, which is not readily understood considering the fact that this country has at least 10 years history of GM crop biotechnology and 30 years of experience of tissue culture technology. What were the problems? Why has the crop biotechnology not been adopted sooner? Generally the tardiness shown by business in adopting GM crop biotechnology is caused by many factors: academical frontline, research funding, professional labor, systems for GM cultivation and risk assessment, understanding and help from the public, industrial success, professional leaders on GM crop development, and so on. Among these, the most critical aspect in Korean science community is the lack of industrial pipeline and interest from seed companies. In most cases, the driving force behind business comes from the private sector and we do not have private companies that are able to conduct the complicated biotechnology. A major question we are holding is what has to be done if we are to catch up in the race for the new green industry promoting people’s health, increasing food availability and protecting natural environment. Here I discuss about the successful events as to GM peppers and what the roadmap for commercialization would be.