Ectopic overexpression of AtHDG11 in tall fescue resulted in enhanced tolerance to drought and salt stress

Tall fescue (Festuca arundinacea Schreb.) is a cool-season perennial grass, which has been conventionally grown in the temperate area. However, as a major type of cool-season turf grass, its growth has been extended to the sub-tropical climate or even to the transitional climate between the sub-tropical and the tropical, and, in some cases, to heavily salinized lands. The extended growth imposes a serious challenge to its tolerance to the abiotic stress, particularly to drought, salt and high temperature. Here, we report a successful introduction of Arabidopsis AtHDG11 into the tall fescue via Agrobacterium-mediated transformation. The ectopic overexpression of AtHDG11 under the control of CaMV 35S promoter with four enhancers resulted in significantly enhanced tolerance to drought and salt stress. No obvious adverse effects on growth and development were observed in the transgenic plants. The enhanced stress tolerance was associated with a more extensive root system, a lower level of malondialdehyde, a nearly normal Na⁺/K⁺ ratio, a higher level of proline and a kinetically accelerated induction of SOD and CAT activities observed in the transgenic plants during drought and/or salt stress, indicating that an enhanced ROS scavenging capability might play a significant role in the acquired tolerance to the abiotic stress. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Ya-Jun Cao and Qiang Wei contributed equally to this work.     

旱作农田不同耕作土壤呼吸及其对水热因子的响应

为研究旱作农田春玉米生育期不同耕作土壤呼吸变化特征及其对水热因子的响应情况,在山西省寿阳县旱农试验基地采用红外气体分析法测定了传统耕作(CT)、少耕(RT)和免耕(NT)土壤呼吸速率,并同步测定了各土层土壤水分、温度.研究表明:在春玉米生育期内,土壤呼吸速率均呈单峰型变化趋势,峰值出现在8月;传统耕作与少耕土壤呼吸速率变化趋势基本一致,而免耕土壤与前两者相比波动幅度较大;土壤呼吸峰值与水分、温度之间无明显相关,其余时期土壤呼吸与水分、温度因子具有良好的相关性;双因子模型较单因子模型能更好的描述土壤呼吸与水分、温度之间关系,基于水热双因子(10-20 cm)的指数-幂模型能够解释土壤呼吸变化的81％-87％ (P＜O.01);3种耕作土壤呼吸对水热因子协同影响的敏感性表现为CT＞NT＞RT.     

利用氧化剂甲基紫精筛选拟南芥寿限延长突变体

在模式动物中的研究表明,寿限延长与氧化胁迫耐受能力密切有关;在模式植物拟南芥中也发现晚花突变体具有更强的抗氧化胁迫能力,但迄今为止未见有关拟南芥寿限延长突变体的研究报道。本文建立了用氧化剂甲基紫精筛选寿限延长突变体的方法,并对用该方法从经快中子诱变的拟南芥Columbia生态型M2代群体中筛选获得的突变体SFNA-9—4进行分析,发现该突变体的抗氧化胁迫能力和寿限均显著增加。由此说明,用该方法筛选拟南芥寿限延长突变体是可行的。     

Boosting the Activity of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ Perovskite for Oxygen Reduction Reactions at Low‐to‐Intermediate Temperatures through Tuning B‐Site Cation Deficiency

Doped perovskite oxides with the general formula of A_xA′_1?xB_yB′_1?yO₃ have been extensively exploited as the cathode materials of solid oxide fuel cells (SOFCs), but the performance at low‐to‐medium temperatures still needs improvement. BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3?δ (BCFZY) has been recently reported to show promising oxygen reduction reaction (ORR) activity under SOFCs' operating conditions. Here, it is reported that the activity of BCFZY can be further boosted via introducing a slight B‐site cation deficiency into the oxide lattice, and such an improvement is assigned to an increase in oxygen mobility that brings enhancement in both surface exchange and bulk diffusion kinetics. Specifically, materials with the nominal composition of Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.975O_3?δ and Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.95O_3?δ show significantly improved activity for ORR at reduced temperatures with the area specific resistances of 0.011 and 0.024 Ω cm² at 600 °C, as a comparison of 0.042 Ω cm² for the cation stoichiometric BCFZY. Excessive B‐site deficiencies, however, lead to the formation of impurity phases, which cause a block for charge transfer and, consequently, a reduction in electrode performance. Introducing a B‐site cation deficiency is a promising way to optimize the activity of perovskite oxides for ORR at reduced temperatures, but the degree of deficiency shall be carefully tuned.     

Drought Stress in Brassica napus: Effects,Tolerance Mechanisms,and Management Strategies

Journal of Plant Growth Regulation - Drought poses serious threats to global crop production and its intensity is continuously soaring due to global warming. Brassica napus L. is an essential...