Enhanced drought and salinity tolerance in transgenic potato plants with a BADH gene from spinach

Zhang, Ning,Si, Huai-Jun,Wen, Gang,Du, Hong-Hui,Liu, Bai-Lin,Wang, Di The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.1

Drought and salinity are the most important abiotic stresses that affect the normal growth and development of plants. Glycine betaine is one of the most important osmolytes present in higher plants that enable them to cope with environmental stresses through osmotic adjustment. In this study, a betaine aldehyde dehydrogenase (BADH) gene from spinach under the control of the stress-induced promoter rd29A from Arabidopsis thaliana was introduced into potato cultivar Gannongshu 2 by the Agrobacterium tumefaciens system. Putative transgenic plants were confirmed by Southern blot analysis. Northern hybridization analysis demonstrated that expression of BADH gene was induced by drought and NaCl stress in the transgenic potato plants. The BADH activity in the transgenic potato plants was between 10.8 and 11.7 U. There was a negative relationship (y = -2.2083x + 43.329, r = 0.9495) between BADH activity and the relative electrical conductivity of the transgenic potato plant leaves. Plant height increased by 0.4-0.9 cm and fresh weight per plant increased by 17-29% for the transgenic potato plants under NaCl and polyethylene glycol stresses compared with the control potato plants. These results indicated that the ability of transgenic plants to tolerate drought and salt was increased when their BADH activity was increased.

The use of JIP test to evaluate drought-tolerance of transgenic rice overexpressing OsNAC10

Redillas, Mark C.F.R.,Strasser, Reto J.,Jeong, Jin-Seo,Kim, Youn-Shic,Kim, Ju-Kon The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.2

In this study, the JIP test was exploited to assess drought-tolerance of transgenic rice overexpressing OsNAC10. Two types of promoters, RCc3 (root-specific) and GOS2 (constitutive), were used to drive the transcription factor OsNAC10, a gene involved in diverse functions including stress responses. Three-month-old plants were exposed to drought for 1 week and their fluorescence kinetics was evaluated. Our results showed that drought-treated non-transgenic plants (NT) have higher fluorescence intensity at the J phase (2 ms) compared to transgenic plants, indicating a decline in electron transport beyond the reduced plastoquinone ($Q_A^-$). As manifested by negative L bands, transgenic plants also showed higher energetic connectivity and stability over NT plants under drought conditions. Also, the pool size of the end electron acceptor at the photosystem I was reduced more in NT than in transgenic plants under drought conditions. Furthermore, the transgenic plants had higher $PI_{total}$, a combined parameter that reflects all the driving forces considered in JIP test, than NT plants under drought conditions. In particular, the $PI_{total}$ of the RCc3:OsNAC10 plants was higher than that of NT plants, which was in good agreement with their differences in grain yield. Thus, the JIP test proved to be practical for evaluating drought-tolerance of transgenic plants.

Functional Screening for Cell Death Suppressors and Development of Multiple Stress-Tolerant Plants

Moon Hae-Jeong,Baek Dong-Won,Lee Ji-Young,Nam Jae-Sung,Yun Dae-Jin The Korean Society of Plant Biotechnology 2003 Plant molecular biology and biotechnology research Vol.5 No.3

Bax, a mammalian pro-apoptotic member of the Bcl-2 family induces cell death when expressed in yeast. To investigate whether Bax expression can induce cell death in plant, we produced transgenic Arabidopsis plants that contained murine Bax cDNA under control of a glucocorticoid-inducible promoter. Transgenic plants treated with dexamethasone, a strong synthetic glucocorticoid, induced Bax accumulation and cell death, suggesting that some elements of cell death mechanism by Bax may be conserved among various organisms. Therefore, we developed novel yeast genetic system, and cloned several Plant Bax Inhibitors (PBIs). Here, we report the function of two PBIs in detail. PBI1 is ascorbate peroxidase (sAPX). Fluorescence method of dihydrorhodamine123 oxidation revealed that expression of Bax in yeast cells generated reactive oxygen species (ROS), and which was greatly reduced by co-expression with sAPX. These results suggest that sAPX inhibits the generation of ROS by Bax, which in turn suppresses Baxinduced cell death in yeast. PBI2 encodes nucleoside diphosphate kinase (NDPK). ROS stress strongly induces the expression of the NDPK2 gene in Arabidopsis thaliana (AtNDPK2). Transgenic plants overexpressing AtNDPK2 have lower levels of ROS than wildtype plants. Mutants lacking AtNDPK2 had higher levels of ROS than wildtype. $H_2O_2$ treatment induced the phosphorylation of two endogenous proteins whose molecular weights suggested they are AtMPK3 and AtMPK6. In the absence of $H_2O_2$ treatment, phosphorylation of these proteins was slightly elevated in plants overexpressing AtNDPK2 but markedly decreased in the AtNDPK2 deletion mutant. Yeast two-hybrid and in vitro protein pull-down assays revealed that AtNDPK2 specifically interacts with AtMPK3 and AtMPK6. Furthermore, AtNDPK2 also enhances the MSP phosphorylation activity of AtMPK3 in vitro. Finally, constitutive overexpression of AtNDPK2 in Arabidopsis plants conferred an enhanced tolerance to multiple environmental stresses that elicit ROS accumulation in situ. Thus, AtNDPK2 appears to playa novel regulatory role in $H_2O_2$-mediated MAPK signaling in plants.

Studies on Genetic Stability of Micropropagated Plants and, Reintroduction in an Endemic and Endangered Taxon: Syzygium travancoricum Gamble (Myrtacae)

Ajith Anand The Korean Society of Plant Biotechnology 2003 Plant molecular biology and biotechnology research Vol.5 No.4

Tissue culture techniques arguably are an important approach for ex situ conservation of rare and endangered plant species. However, there is utmost importance on maintaining the genetic integrity of the introduced plants especially in tree species. To examine the genetic integrity of the micropropagated plants, we randomly screened few hardened plants of Syzygium travancoricum, a critically endangered tree taxon, using Randomly Amplified Polymorphic DNA (RAPD) markers. Twenty-three random. primers were tried and twenty-five polymorphic loci were identified. The dendrogram based on the Unweighted Pair-Group Method Arithmetic Average and Nei's similarity index depicted about 97% homology between the mother plants and micropropagated plants. Further, an attempt was made to reintroduce the micropropagated plants in the wild. Over three hundred small trees could be successfully established.

The Expression of Egg Plant Flavonoid 3',5'-Hydroxylase Gene in Tobacco Plants (Nicotiana tabacum cv. Xanthi)

Park, Sun-Young,Kim, Younghee The Korean Society of Plant Biotechnology 2000 Plant molecular biology and biotechnology research Vol.2 No.1

The anthocyanin gene encoding flavonoid 3',5'-hydroxylase(F3,5H) was normally expressed in Nicotiana tobacco (Xanthi) plants cocultivated with Agrobacterium tumefaciens LBA4404 carrying egg plant flavonoid 3',5'-hydroxylase cDNA. Northern blot analysis showed the normal expression of F3', 5'H gene from transgenic plants. Here we found the phenotypic differences between transgenic plants and wild-type plants. The petal shape of transgenic plants showed more round shape and around petal tube area was compared to that of wild-type tobacco plants. And the petal color of transgenic plants was much lighter than that of wild-type tobacco plants.

Use of plant growth-promoting rhizobacteria to control stress responses of plant roots

Kang, Bin-Goo,Kim, Woo-Taek,Yun, Hye-Sup,Chang, Soo-Chul The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.3

Ethylene is a key gaseous hormone that controls various physiological processes in plants including growth, senescence, fruit ripening, and responses to abiotic and biotic stresses. In spite of some of these positive effects, the gas usually inhibits plant growth. While chemical fertilizers help plants grow better by providing soil-limited nutrients such as nitrogen and phosphate, overusage often results in growth inhibition by soil contamination and subsequent stress responses in plants. Therefore, controlling ethylene production in plants becomes one of the attractive challenges to increase crop yields. Some soil bacteria among plant growth-promoting rhizobacteria (PGPRs) can stimulate plant growth even under stressful conditions by reducing ethylene levels in plants, hence the term "stress controllers" for these bacteria. Thus, manipulation of relevant genes or gene products might not only help clear polluted soil of contaminants but contribute to elevating the crop productivity. In this article, the beneficial soil bacteria and the mechanisms of reduced ethylene production in plants by stress controllers are discussed.

Biotechnology of Reproductive Processes in Cereals

Barnabas, Beata The Korean Society of Plant Biotechnology 1999 JOURNAL OF PLANT BIOTECHNOLOGY Vol.1 No.1

Sexual reproduction is an essential process in the propagation of flowering plants. Recent advances in plant cell biology and biotechnology have brought new and powerful methodologies to investigate and manipulate the reproductive processes of angiosperms including agronomically important crop plants. Successful cryopreservation of maize, rye and triticale pollen and young embryos of microspore-and zygote-origine contributes to long term preservation of important plant germ-lines in gene banks. Discovering morphogenetic characteristics of the different developmental pathways taking place in wheat and maize androgenesis in vitro helps to influence the procedure to produce genetically and phenotipically stable homozygous doubled haploid plants for breeding purposes. Detailed ultrastructural and cell-biological studies on the developmental sequences of male and female gametophyte development in wheat, experimental protocols developed to isolate and micromanipulate egg cell protoplasts, make it possible to use plant gametes and the sexual route itself to produce genetically improved organisms. Plant gametes can become useful tools for crop improvement in the near future. Recent achievements by our laboratory in this field are reviewed in the present paper

Influences of different light sources and light/dark cycles on anthocyanin accumulation and plant growth in Petunia

Ai, Trinh Ngoc,Naing, Aung Htay,Kim, Chang Kil The Korean Society of Plant Biotechnology 2016 식물생명공학회지 Vol.43 No.1

Anthocyanin accumulation and plant growth were examined in petunia (NT and $T_2$ transgenic plants) by determining the effects of different sources of light and varying light/dark cycles. Red light significantly enhanced anthocyanin content of B-peru+mPAP1; however, it had a negative effect on anthocyanin production in RsMYB1 plants. In general, white light was found to be reasonable for anthocyanin accumulation in all plants. In case of light/dark cycles, application of seven days of light:14 days of dark significantly enhanced anthocyanin content. We found that anthocyanin content detected in transgenic plants expressing anthocyanin regulatory transcription factor genes (B-peru+mPAP1 or RsMYB1) was higher than that in NT plants in all treatments. Plant growth was also influenced by the different light sources and dark/light cycles. Taken together, our results suggest that light source and light/dark cycle play an important role in anthocyanin production and plant growth. The choice of the optimal conditions is also important for anthocyanin production and plant growth depending on NT or transgenic plants carrying anthocyanin regulatory transcription factors.

Expression of Dengue virus EIII domain-coding gene in maize as an edible vaccine candidate

Kim, Hyun A,Kwon, Suk Yoon,Yang, Moon Sik,Choi, Pil Son The Korean Society of Plant Biotechnology 2014 식물생명공학회지 Vol.41 No.1

Plant-based vaccines possess some advantages over other types of vaccine biotechnology such as safety, low cost of mass vaccination programs, and wider use of vaccines for medicine. This study was undertaken to develop the transgenic maize as edible vaccine candidates for humans. The immature embryos of HiII genotype were inoculated with A. tumefaciens strain C58C1 containing the binary vectors (V662 or V663). The vectors carrying nptII gene as selection marker and scEDIII (V662) or wCTB-scEDIII (V663) target gene, which code EIII proteins inhibite viral adsorption by cells. In total, 721 maize immature embryos were transformed and twenty-two putative transgenic plants were regenerated after 12 weeks selection regime. Of them, two- and six-plants were proved to be integrated with scEDIII and wCTB-scEDIII genes, respectively, by Southern blot analysis. However, only one plant (V662-29-3864) can express the gene of interest confirmed by Northern blot analysis. These results demonstrated that this plant could be used as a candidated source of the vaccine production.

Overproduction of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) confers resistance to the herbicide glyphosate in transgenic rice

Lee, Soo-In,Kim, Hyun-Uk,Shin, Dong-Jin,Kim, Jin-A,Hong, Joon-Ki,Kim, Young-Mi,Lee, Yeon-Hee,Koo, Bon-Sung,Kwon, Sun-Jong,Suh, Seok-Chul The Korean Society of Plant Biotechnology 2011 식물생명공학회지 Vol.38 No.4

Plants expressing Agrobacterium sp. strain CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) are known to be resistant to glyphosate, a potent herbicide that inhibits the activity of the endogenous plant EPSPS. In order to develop herbicide-resistant rice, we prepared transgenic rice plants with CP4 EPSPS gene under the control of CaMV 35S promoter for over-expression. A recombinant plasmid was transformed into rice via Agrobacterium-mediated transformation. A large number of transgenic rice plants were obtained with glyphosate and most of the transformants showed fertile. The integration and expression of CP4 EPSPS gene from regenerated plants was analyzed by Southern and northern blot analysis. The transgenic rice plants had CP4 EPSPS enzyme activity levels more than 15-fold higher than the wild-type plants. EPSPS enzyme activity of transgenic rice plants was also identified by strip-test method. Field trial of transgenic rice plants further confirmed that they can be selectively survived at 100% by spay of glyphosate (Roundup$^{(R)}$) at a regular dose used for conventional rice weed control.