Stress-induced expression of the sweetpotato gene <i>IbLEA14</i> in poplar confers enhanced tolerance to multiple abiotic stresses

Ke, Qingbo,Park, Sung-Chul,Ji, Chang Yoon,Kim, Ho Soo,Wang, Zhi,Wang, Shiwen,Li, Hongbing,Xu, Bingcheng,Deng, Xiping,Kwak, Sang-Soo Elsevier 2018 Environmental and experimental botany Vol.156 No.-

<P><B>Abstract</B></P> <P>Late embryogenesis abundant (LEA) proteins are small, highly hydrophilic proteins that act as protectors of macromolecules and increase abiotic stress tolerance in plants. We previously reported that overexpressing sweetpotato <I>IbLEA14</I> under the control of the <I>CaMV 35S</I> promoter increased osmotic and salt stress tolerance in transgenic sweetpotato calli. In this study, we generated transgenic poplar plants (<I>Populus alba × P. glandulosa</I>) expressing <I>IbLEA14</I> under the control of the oxidative stress-inducible <I>SWPA2</I> promoter (referred to as SL plants). Among the 15 SL plants obtained, three lines (SL2, SL7, and SL12) were established based on <I>IbLEA14</I> transcript levels, tolerance to salt stress and Southern blot analysis. The SL plants exhibited less damage in response to methyl viologen-mediated oxidative stress than non-transgenic (NT) plants. SL plants also showed enhanced tolerance to drought, salt, and heat stress, which was associated with higher photosystem II efficiency and lower malondialdehyde levels compared with NT plants. Furthermore, SL plants had higher levels of monolignol biosynthesis-related gene transcripts under drought stress compared with NT plants. Finally, SL plants exhibited increased tolerance to heat stress, which is associated with the high thermostability of IbLEA14 protein. SL plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>IbLEA14</I> gene was transformed into poplar plants. </LI> <LI> Transgenic poplars exhibit increased tolerance to MV-mediated oxidative, drought, salt and heat stress. </LI> <LI> Overproduction of IbLEA14 affects lignification and thermostability of transgenic poplars. </LI> </UL> </P>

Down‐regulation of <i>GIGANTEA</i> ‐ <i>like</i> genes increases plant growth and salt stress tolerance in poplar

Ke, Qingbo,Kim, Ho Soo,Wang, Zhi,Ji, Chang Yoon,Jeong, Jae Cheol,Lee, Haeng‐,Soon,Choi, Young‐,Im,Xu, Bingcheng,Deng, Xiping,Yun, Dae‐,Jin,Kwak, Sang‐,Soo John Wiley and Sons Inc. 2017 Plant biotechnology journal Vol.15 No.3

<P><B>Summary</B></P><P>The flowering time regulator GIGANTEA (GI) connects networks involved in developmental stage transitions and environmental stress responses in <I>Arabidopsis</I>. However, little is known about the role of GI in growth, development and responses to environmental challenges in the perennial plant poplar. Here, we identified and functionally characterized three <I>GI‐like</I> genes (<I>PagGIa</I>,<I> PagGIb</I> and <I>PagGIc)</I> from poplar (<I>Populus alba × Populus glandulosa</I>). <I>PagGIs</I> are predominantly nuclear localized and their transcripts are rhythmically expressed, with a peak around zeitgeber time 12 under long‐day conditions. Overexpressing <I>PagGIs</I> in wild‐type (WT) <I>Arabidopsis</I> induced early flowering and salt sensitivity, while overexpressing <I>PagGIs</I> in the <I>gi‐2</I> mutant completely or partially rescued its delayed flowering and enhanced salt tolerance phenotypes. Furthermore, the PagGIs‐PagSOS2 complexes inhibited PagSOS2‐regulated phosphorylation of PagSOS1 in the absence of stress, whereas these inhibitions were eliminated due to the degradation of PagGIs under salt stress. Down‐regulation of <I>PagGIs</I> by RNA interference led to vigorous growth, higher biomass and enhanced salt stress tolerance in transgenic poplar plants. Taken together, these results indicate that several functions of <I>Arabidopsis GI</I> are conserved in its poplar orthologues, and they lay the foundation for developing new approaches to producing salt‐tolerant trees for sustainable development on marginal lands worldwide.</P>

Preparation of Copper Nanoparticles Coated Cotton Fabrics with Durable Antibacterial Properties

Qingbo Xu,Xiating Ke,Naiqin Ge,Liwen Shen,Yanyan Zhang,Feiya Fu,Xiangdong Liu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

When copper nanoparticles (Cu NPs) were applied as an antimicrobial agent to finish cotton fabrics, there are two issues should be solved: the oxidization and the weak adsorbability onto cotton fiber surface. In the present work, we developed a new method that can achieve both immobilization and protection of the Cu NPs at the same time. As an effective binder, thioglycolic acid (TGA) was covalently linked to cotton fiber surface via an esterification with the hydroxyl groups of cellulose, then Cu NPs were introduced on the fabric surface in the presence of a protective reagent, citric acid. Due to the doubled stabilization acts of TGA and citric acid, the Cu NPs immobilized on the fabric surface showed an excellent antibacterial effect and outstanding laundering durability. Even after 50 consecutive laundering tests, the modified cotton fabrics still showed satisfactory antibacterial ability against both S. aureus and E. coli, which the bacterial reduction rates are all higher than 96 %. It is believed that this methodology has potential applications in a wide variety of textile productions such as sportswear, socks, and medical textiles.

Facile Fabrication of Durable Antibacterial Cotton Fabric Realized by Thioglycolic Acid and Silver Nanoparticles

Qingbo Xu,Xiating Ke,Yanyan Zhang,Feiya Fu,Xiangdong Liu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.11

In this study, durable antibacterial cotton fabrics were prepared by a simple two-step impregnation method. Firstly, thioglycolic acid (TGA) was grafted onto cotton fabric via esterification with the hydroxyl groups of cellulose, then silver nanoparticles (Ag NPs) were immobilized on the cotton fabric surface via coordination bonds with the TGA thiol groups. As a result, the mean size of Ag NPs coating on the cotton fabric is around 74 nm, and these functionalized cotton fabrics show superior antibacterial properties and excellent laundering durability. After withstand 50 laundering cycles, the obtained cotton fabrics still showed outstanding bacterial reduction rates (BR) against both S. aureus and E. coli, and the rates are all higher than 97 %. Therefore, this method to prepare antibacterial cotton fabric shows great potential applications in socks, cosmetic, and medical textiles.

Preparation of Durable Superhydrophobic Cotton Fabric for Selfcleaning and Oil-water Separation

Qingbo Xu,Xiating Ke,Yanyan Zhang,Peng Wang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6

Improving the surface roughness and reducing the surface energy are the main strategies for constructing cottonfabrics with superhydrophobic surface. However, the complex finishing process and poor durability still impede theproduction and application of superhydrophobic cotton fabrics. Therefore, it is critical to produce superhydrophobic fabricswith excellent durability via a noncomplicated method. In this work, monomers of methyl methacrylate (MMA) andtrifluoroethyl methacrylate (TFMA) were polymerized via free radical polymerization to produce a fluoropolymer. Then, thefabric was coated with the fluoropolymer to construct a superhydrophobic surface via the pad-dry-cure technology. TheTFMA unit in the fluoropolymer had lower surface energy than the MMA unit. Under the high-temperature curing condition,the MMA unit in the fluoropolymer was grafted onto the cotton fabric via transesterification, and the TFMA was exposed onthe fabric surface. The finished fabric showed durable superhydrophobic properties, outstanding oil-water separationproperties, and excellent self-cleaning properties. Given the results, the finished fabric has great potential application inclothing and industrial fields.

Suppression of the <i>β-carotene hydroxylase</i> gene increases β-carotene content and tolerance to abiotic stress in transgenic sweetpotato plants

Kang, Le,Ji, Chang Yoon,Kim, Sun Ha,Ke, Qingbo,Park, Sung-Chul,Kim, Ho Soo,Lee, Hyeong-Un,Lee, Joon Seol,Park, Woo Sung,Ahn, Mi-Jeong,Lee, Haeng-Soon,Deng, Xiping,Kwak, Sang-Soo Elsevier 2017 Vol. No.

<P><B>Abstract</B></P> <P>β-carotene, a carotenoid that plays a key photo-protective role in plants is converted into zeaxanthin by β-carotene hydroxylase (CHY-β). Previous work showed that down-regulation of <I>IbCHY-β</I> by RNA interference (RNAi) results in higher levels of β-carotene and total carotenoids, as well as salt stress tolerance, in cultured transgenic sweetpotato cells. In this study, we introduced the RNAi-<I>IbCHY-β</I> construct into a white-fleshed sweetpotato cultivar (cv. Yulmi) by <I>Agrobacterium</I>-mediated transformation. Among the 13 resultant transgenic sweetpotato plants (referred to as RC plants), three lines were selected for further characterization on the basis of <I>IbCHY-β</I> transcript levels. The RC plants had orange flesh, total carotenoid and β-carotene contents in storage roots were 2-fold and 16-fold higher, respectively, than those of non-transgenic (NT) plants. Unlike storage roots, total carotenoid and β-carotene levels in the leaves of RC plants were slightly increased compared to NT plants. The leaves of RC plants also exhibited tolerance to methyl viologen (MV)-mediated oxidative stress, which was associated with higher 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical-scavenging activity. In addition, RC plants maintained higher levels of chlorophyll and higher photosystem II efficiency than NT plants after 250 mM NaCl stress. Yield of storage roots did not differ significantly between RC and NT plants. These observations suggest that RC plants might be useful as a nutritious and environmental stress-tolerant crop on marginal lands around the world.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Transgenic sweet potato plants were generated by RNAi silencing of the <I>IbCHY-β</I> gene. </LI> <LI> Transgenic sweet potato plants had increased β-carotene and total carotenoid content. </LI> <LI> Transgenic sweet potato plants exhibited strong antioxidant capacity and salt stress tolerance. </LI> </UL> </P>

Overexpression of alfalfa <i>Orange</i> gene in tobacco enhances carotenoid accumulation and tolerance to multiple abiotic stresses

Wang, Zhi,Xu, Weizhou,Kang, Jiyue,Li, Min,Huang, Jin,Ke, Qingbo,Kim, Ho Soo,Xu, Bingcheng,Kwak, Sang-Soo Elsevier 2018 Vol. No.

<P><B>Abstract</B></P> <P>The multifunctional Orange (Or) protein plays crucial roles in carotenoid homeostasis, photosynthesis stabilization, and antioxidant activity in plants under various abiotic stress conditions. The <I>Or</I> gene has been cloned in several crops but not in alfalfa (<I>Medicago sativa</I> L.). Alfalfa is widely cultivated across the world; however, its cultivation is largely limited by various abiotic stresses, including drought. In this study, we isolated the <I>Or</I> gene from alfalfa (<I>MsOr</I>) cv. Xinjiang Daye. The amino acid sequence of the deduced MsOr protein revealed that the protein contained two trans-membrane domains and a DnaJ cysteine-rich zinc finger domain, and showed a high level of similarity with the Or protein of other plants species. The MsOr protein was localized in leaf chloroplasts of tobacco. The expression of <I>MsOr</I> was the highest in mature leaves and was significantly induced by abiotic stresses, especially drought. To perform functional analysis of the <I>MsOr</I> gene, we overexpressed <I>MsOr</I> gene in tobacco (<I>Nicotiana benthamiana</I>). Compared with wild-type (WT) plants, transgenic tobacco lines showed higher carotenoid accumulation and increased tolerance to various abiotic stresses, including drought, heat, salt, and methyl viologen-mediated oxidative stress. Additionally, contents of hydrogen peroxide and malondialdehyde were lower in the transgenic lines than in WT plants, suggesting superior membrane stability and antioxidant capacity of TOR lines under multiple abiotic stresses. These results indicate the <I>MsOr</I> gene as a potential target for the development of alfalfa cultivars with enhanced carotenoid content and tolerance to multiple environmental stresses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Orange (<I>MsOr</I>) gene from alfalfa was isolated and characterized in transgenic tobacco. </LI> <LI> <I>MsOr</I> gene was localized to chloroplasts and strongly induced by abiotic stresses including drought. </LI> <LI> <I>MsOr</I> expressing tobacco plants showed enhanced tolerance to drought, heat, salt and oxidative stress. </LI> </UL> </P>

Meta-analysis of the effect of melatonin application on abiotic stress tolerance in plants

Yang Xiaoxiao,Ren Jianhong,Li Juanjuan,Lin Xinyue,Xia Xiangyu,Yan Wenjie,Zhang Yuxin,Deng Xiping,Ke Qingbo 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.1

Melatonin is a hormone-like substance that promotes plant growth and development and alleviates stress levels. Although the physiological roles of melatonin and the underlying mechanisms have been qualitatively reviewed in plants, we do not fully understand when and how to apply melatonin to maximize its benefits. Here, we performed a meta-analysis to quantitatively evaluate the effect of melatonin on abiotic stress tolerance in plants and to determine the number of parameters modulated by melatonin. Melatonin significantly alleviated the growth inhibition induced by drought stress compared with other abiotic stresses, including salt, cold, heat, nitrogen deficit, and heavy metal toxicity, mainly owing to higher photosynthesis efficiency and antioxidant enzyme activity. Furthermore, melatonin modulated plant growth in a concentration-dependent manner and was more effective when applied to plants under moderate drought stress at an early stage via root irrigation. In addition, the impact of melatonin was greater in monocots than in dicots. Moreover, endogenous melatonin levels could be significantly increased via transgenic strategies. Among melatonin biosynthesis-related gene members, ASMT has tended to have the most influence on melatonin content in plants. In light of the rapidly developing genome editing technology, quantitatively increasing endogenous melatonin level in plant would be quite useful for moderating climatic conditions and combating desertification. Taken together, our results provide guidelines for melatonin application in crops plants for improving productivity under ongoing climate change.

Dryland agricultural environment and sustainable productivity

Gou-Xia Li,Bing-Cheng Xu,Li-Na Yin,Shi-Wen Wang,Sui-Qi Zhang,Lun Shan,곽상수,Qingbo Ke,Xi-Ping Deng 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.2

Global climate change is expected to cause progressively increased frequency and severity of drought events, which further seriously limit plant growth and crop yields. Increasing water use effi ciency (WUE) and yield per unit rainfall are one of the most important challenges in dry land agriculture. Here, we reviewed the comprehensive technical strategies including conserving water to combine both increased agricultural productivity and resource conservation; enquiring into how crop plants respond to drought through morphological, physiological, and molecular modifi cations that occur in all plant organs; breeding for drought tolerance where there is a delineated stress environment and genotype × environment interactions are stable; eff ective conservation of rainfall and high effi ciency of use. In addition, we discussed the preponderance of biological water-saving measures, which embraces improvements in WUE and drought tolerance, by genetic improvement and physiological regulation. Sustainable agriculture would be benefi ted from modern engineering such as biological engineering, conservation tillage, and breeding technologies.

Overexpression of the potato StEPF2 gene confers enhanced drought tolerance in Arabidopsis

Yanli Wang,Tian Xie,Chunli Zhang,Juanjuan Li,Zhi Wang,Hongbing Li,Xiping Liu,Li-Na Yin,Shi-Wen Wang,Sui-Qi Zhang,Xiping Deng,Qingbo Ke 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.4

Epidermal patterning factor 2 (EPF2) is a negative regulator of stomatal development, and is essential for plant growth, development, and environmental stress responses. However, the role of EPF2 in potato (Solanum tuberosum) has not been investigated to date. Here, we cloned and characterized the potato EPF2-like gene (StEPF2). StEPF2 is predominantly intercellular space localized and its transcripts were rhythmically expressed, and showed the highest expression in apical unexpanded leaves. Expression of StEPF2 was markedly down-regulated in response to abscisic acid and sodium chloride treatments; however, upon the application of polyethylene glycol, the expression of StEPF2 peaked at 4 h and then decreased gradually. Overexpression of StEPF2 in Arabidopsis (OE) substantially reduced stomatal density and photosynthetic rate, but had little effects on plant growth. Under drought stress, OE lines maintained higher photosynthetic rates, photosystem II efficiency, and instantaneous water use efficiency than wild-type (WT) plants. Moreover, OE lines showed less water loss and hydrogen peroxide accumulation in detached leaves compared with WT plants. Thus, our results suggest that StEPF2 acts as a negative regulator of stomatal development in potato, indicating that the role of EPF2 is conserved across plant species. Overall, StEPF2 represents an important target for the development of drought-tolerant potato cultivars via genetic engineering.