大球盖菇的生物学基础、活性成分及其应用

大球盖菇是联合国粮农组织向发展中国家推荐栽培的食用菌之一,对农作物秸秆及林木枝条、落叶等有较强的降解能力。通过人工种植可培养营养丰富、美味可口的大球盖菇子实体产品,其菌渣还能够改善土壤环境,在生态农林产业及循环经济等方面具有重要作用。本文从大球盖菇的生物学基础、子实体营养、生物活性成分及其在农林生态和环境修复应用等角度进行综述,为大球盖菇的进一步开发利用及其相关产业发展提供参考。     

粮食上木霉菌的分离鉴定及其生防效果

【背景】粮食在生长和收储期极易受到病原真菌或产毒真菌的污染,造成严重的损失。众多实践证明木霉属(Trichoderma)可以有效防治植物病原真菌。【目的】鉴定和筛选能有效抑制粮食常见危害真菌的木霉生防菌株,开发生防菌剂,保障粮食生产安全。【方法】从粮食上分离筛选出35株木霉,通过多基因系统发育分析和形态学观察方法进行菌种鉴定,利用平板对峙试验筛选出对粮食常见危害真菌有抑制作用的菌株。【结果】35株木霉分属于8个种,分别为非洲哈茨木霉(Trichodermaafroharzianum)、类棘孢木霉(Trichodermaasperelloides)、 Trichoderma amoenum、近深绿木霉(Trichoderma paratroviride)、Trichoderma obovatum、长枝木霉(Trichoderma longibrachiatum)、东方木霉(Trichodermaorientale)和深绿木霉(Trichodermaatroviride)。对峙试验结果表明,这8种木霉对于粮食上分离到的10种危害真菌均具有较好的抑制效果。非洲哈茨木霉(T.afroharzi...     

极地微生物资源的研究现状及挑战

南极和北极区域存在着苔原、冻土、海洋、冰川、湖泊和高山等多种地质地貌,其低温、干燥、强辐射和贫瘠等环境形成了独特而多样化的微生物群落,是微生物资源的宝库。本文对极地微生物的低温酶、多糖以及其代谢产物(抗菌活性物质、表面活性剂、色素、挥发性有机物等)的功能和应用进行了概述,综述了极地微生物及其模式菌株的种类和保藏量,以及极地微生物专利申请和相关研究机构的现况,探讨了在极地微生物勘探中关于可培养性、宏基因组方法以及大数据的挑战。     

Sub-Cellular Distribution of Zinc in Different Vegetative Organs and Their Contribution to Grains Zinc Accumulation in Rice Under Different Nitrogen and Zinc Supply

Journal of Plant Growth Regulation - Zinc is an important micronutrient for the growth and development of human body and plants. Proper use of nitrogen fertilizer and foliar application of Zn have...     

Nitric Oxide Enhances Salt Tolerance in Tomato Seedlings by Regulating Endogenous S-nitrosylation Levels

Salinity impairs plant growth and development, thereby leading to low yield and inferior quality of crops. Nitric oxide (NO) has emerged as an essential signaling molecule that is involved in regulating various physiological and biochemical processes in plants. In this study, tomato seedlings of Lycopersicum esculentum L. “Micro-Tom” treated with 150 mM sodium chloride (NaCl) conducted decreased plant height, total root length, and leaf area by 25.43%, 24.87%, and 33.67%, respectively. While nitrosoglutathione (GSNO) pretreatment ameliorated salt toxicity in a dose-dependent manner and 10 µM GSNO exhibited the most significant mitigation effect. It increased the plant height, total root length, and leaf area of tomato seedlings, which was 31.44%, 20.56%, and 51.21% higher than NaCl treatment alone, respectively. However, NO scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide potassium (cPTIO) treatment reversed the positive effect of NO under salt stress, implying that NO is essential for the enhancement of salt tolerance. Additionally, NaCl?+?GSNO treatment effectively decreased O^2? production and H₂O₂ content, increased the levels of soluble sugar, glycinebetaine, proline, and chlorophyll, and enhanced the activities of antioxidant enzymes and the content of antioxidants in tomato seedlings in comparison with NaCl treatment, whereas NaCl?+?cPTIO treatment significantly reversed the effect of NO under salt stress. Moreover, we found that GSNO treatment increased endogenous NO content, S-nitrosoglutathione reductase (GSNOR) activity, GSNOR expression and total S-nitrosylated level, and decreased S-nitrosothiol (SNO) content under salt stress, implicating that S-nitrosylation might be involved in NO-enhanced salt tolerance in tomatoes. Altogether, these results suggest that NO confers salt tolerance in tomato seedlings probably by the promotion of photosynthesis and osmotic balance, the enhancement of antioxidant capability and the increase of protein S-nitrosylation levels.

     

Seed Priming with Gibberellin Regulates the Germination of Cotton Seeds Under Low-Temperature Conditions

Journal of Plant Growth Regulation - Exogenous substances play an important role in the response of cotton to low-temperature conditions during the germination stage, but little is known about the...     

Comprehensive Evaluation and Screening for 1,2,4-Trichlorobenzene Tolerance in Rice Cultivars at Different Growth Stages

Journal of Plant Growth Regulation - 1,2,4-trichlorobenzene (1,2,4-TCB) pollution in fields has become a potential threat to rice growth, yet little is known about the different response of many...     

Regulation of Nitrogen Metabolism,Photosynthetic Activity,and Yield Attributes of Spring Wheat by Nitrogen Fertilizer in the Semi-arid Loess Plateau Region

It is critical for spring wheat (Triticum aestivum L.) production in the semi-arid Loess Plateau to understand the impact of nitrogen (N) fertilizer on changes in N metabolism, photosynthetic parameters, and their relationship with grain yield and quality. The photosynthetic capacity of flag leaves, dry matter accumulation, and N metabolite enzyme activities from anthesis to maturity were studied on a long-term fertilization trial under different N rates [0 kg ha^?1(N1), 52.5 kg ha^?1 (N2), 105 kg ha^?1 (N3), 157.5 kg ha^?1 (N4), and 210 kg ha^?1 (N5)]. It was observed that N3 produced optimum total dry matter (5407 kg ha^?1), 1000 grain weight (39.7 g), grain yield (2.64 t ha^?1), and protein content (13.97%). Our results showed that N fertilization significantly increased photosynthetic parameters and N metabolite enzymes at all growth stages. Nitrogen harvest index, partial productivity factor, agronomic recovery efficiency, and nitrogen agronomic efficiency were decreased with increased N. Higher N rates (N3–N5) maintained higher photosynthetic capacity and dry matter accumulation and lower intercellular CO₂ content. The N supply influenced NUE by improving photosynthetic properties. The N3 produced highest chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate, grain yield, grain protein, dry matter, grains weight, and N metabolite enzyme activities compared to the other rates (N1, N2, N4, and N5). Therefore, increasing N rates beyond the optimum quantity only promotes vegetative development and results in lower yields.

     

The Effect of High-Temperature Stress on the Physiological Indexes,Chloroplast Ultrastructure,and Photosystems of two Herbaceous Peony Cultivars

In this study, two herbaceous peony cultivars with different heat tolerances (‘Fenyunu’ FYN low sensitivity and ‘Qiaoling’ QL high sensitivity) were used as research materials. An integrated view of the factors underlying the decrease in photosynthetic rate under high-temperature (HT) stress was provided by analyzing the biochemical parameters, chloroplast ultrastructure, gas-exchange parameters, chlorophyll fluorescence, and modulated 820 nm reflection of herbaceous peony leaves. The results showed that hydrogen peroxide, superoxide anion, malondialdehyde, and electrical conductivity increased significantly, while the photosynthetic pigments content and photosynthetic capacity decreased significantly in QL than in FYN under HT. The contents of soluble sugars and proline increased greatly in FYN than in QL, while the activity of SOD decreased markedly in QL than in FYN after HT. Compared with FYN, the ultrastructure of QL was more seriously disrupted under HT. Chlorophyll fluorescence analysis showed that HT changed the shapes of OJIP curve, resulting in the increase of K phase and J phase. The PSII acceptor side was more damaged than the donor side, and the electron transfer was seriously blocked. The energy flow in the process of light energy absorption, capture, and electron transfer were significantly changed after HT stress. Meanwhile, PSI was also significantly inhibited, and the coordination of both photosystems decreased. The variation of these parameters in FYN was less than that in QL. These results suggested that FYN featured a more heat-tolerance ability as evidenced by the good performances on the antioxidant system, osmoregulatory capacity, and the thermostability of membranes and photosystems.

     

Fulvic Acid,Brassinolide, and Uniconazole Mediated Regulation of Morphological and Physiological Traits in Maize Seedlings Under Water Stress

Water stress is one of the most important factors limiting sustainable crop production. Therefore, the effects of the plant growth regulators (PGRs) fulvic acid (FA), brassinolide (BR), and uniconazole (Uni) on seedling growth and physiology of two maize (Zea mays L.) varieties were evaluated under???0.7 MPa water stress induced by polyethylene glycol-6000. Under drought stress, the PGRs promoted seedling growth, altered the root-to-shoot ratio, and significantly increased root biomass, length, surface area, diameter, and volume. In addition, depending on the PGR, net photosynthesis rate, SPAD value (indicating chlorophyll content), and water use efficiency increased significantly, under drought stress, whereas transpiration rate decreased. The PGRs also significantly increased antioxidant enzyme activities and significantly decreased malondialdehyde accumulation in leaves and roots under drought stress. Zhengdan958 showed greater variation in physiological responses and stronger drought resistance than Xundan20. In alleviating drought stress in maize seedlings, FA had the greatest effects on shoot growth and leaf physiology; Uni exerted its effects by regulating root structure, and BR effects were intermediate. Under drought stress, the three PGRs increased maize seedling growth, which reduced drought stress-induced damage and improved plant ability to resist the adversity. Based on a comprehensive analysis of physiological indices of drought resistance, Uni is recommended as the best PGR to improve maize seedlings resistance to drought.