Functional Plant Biology最新文献

Non-photochemical quenching and limitations of the photosystem I and photosystem II activities were studied in C3 -plant barley and C4 -plant maize. Plants were exposed to prolonged heat stress under high and low air humidity. Both species decreased non-photochemical quenching at 37-42°C, which increased at 46°C. A decrease of photosystem II activity at 46°C in lower air humidity was achieved through different mechanisms. In barley, photosystem II was downregulated by the increase of non-photochemical quenching. In maize, photosystem II was downregulated by the increase of acceptor-side limitation. Analysis of transients also revealed differences between species. One second after a light induction, limitations flashes at the acceptor sides of both photosystems. Elevating the temperature decreased these flashes; acceptor-side limitations of both photosystems decreased proportional to each other. In maize, the size of flashes slightly diminished at 37°C and decreased more at 42-46°C. In barley, the size of flashes greatly decreased at 37°C and gradually returned to the control level under higher temperatures. Around photosystem II, the flash was quenched by a burst of non-photochemical quenching. In barley, the transient peaks of acceptor-side limitation and non-photochemical quenching were very similar at any temperature. This was not observed in maize.

Use of fossil fuels causes environmental issues due to its inefficiency and and imminent depletion. This has led to interest in identifying alternative and renewable energy sources such as biofuel generation from photosynthetic organisms. A wide variety of prokaryotic and eukaryotic microorganisms, known as microalgae, have the potential to be economical and ecologically sustainable in the manufacture of biofuels such as bio-hydrogen, biodiesel, bio-oils, and bio-syngas. By using contemporary bioengineering techniques, the innate potential of algae to produce biomass of superior quality may be enhanced. In algal biotechnology, directed genome modification via RNA-guided endonucleases is a new approach. CRISPR/Cas systems have recently been frequently used to modify the genetic makeup of several aquatic and freshwater microalgae. The majority of research has used the Cas9-driven Type II system, one of two classes and six unique kinds of CRISPR systems, to specifically target desired genes in algae, and knock them out and down, or both. Using CRISPR technology to modify its genetic makeup, microalgae has produced more biomass and increased in lipid content. This review highlights the attempts made so far to target microalgae genome modification, discusses the prospects for developing the CRISPR platform for large-scale genome modification of microalgae, and identifies the opportunities and challenges in the development and distribution of CRISPR/Cas9 components.

We applied a systems biology approach to gain a deep insight into the regulatory mechanisms of barley (Hordeum vulgare ) under drought and waterlogging stress conditions. To identify informative models related to stress conditions, we constructed meta-analysis and two distinct weighted gene co-expression networks. We then performed module trait association analyses. Additionally, we conducted functional enrichment analysis of significant modules to shed light on the biological performance of underlying genes in the two contrasting stresses. In the next step, we inferred the gene regulatory networks between top hub genes of significant modules, kinases, and transcription factors (TFs) using a machine learning algorithm. Our results showed that at power=10, the scale-free topology fitting index (R2) was higher than 0.8 and the connectivity mean became stable. We identified 31 co-expressed gene modules in barley, with 13 and 14 modules demonstrating significant associations with drought and waterlogging stress, respectively. Functional enrichment analysis indicated that these stress-responsive modules are involved in critical processes, including ADP-rybosylation factors (ARF) protein signal transduction, ethylene-induced autophagy, and phosphoric ester hydrolase activity. Specific TFs and kinases, such as C2C2-GATA, HB-BELL, and MADS-MIKC, were identified as key regulators under these stress conditions. Furthermore, certain TFs and kinases established unique connections with hub genes in response to waterlogging and drought conditions. These findings enhance our understanding of the molecular networks that modulate barley's response to drought and waterlogging stresses, offering insights into the regulatory mechanisms essential for stress adaptation.

Whilst temperature (T ) increase on tree function has been well studied, the associated effect of vapour pressure deficit (VPD) is less clear. We investigated the impact of increasing T and VPD on canopy transpiration rate (E ), shoot gas exchange, and stem growth in Norway spruce (Picea abies ) saplings grown in organic and mineral soils in climate chambers with three treatment conditions for 12weeks: (1) 'ambient' (VPD≈0.5kPa); (2) 'highT' treatment (+3°C relative to ambient; VPD≈0.6kPa); and (3) 'highT/lowRH' treatment (+3°C and -7% RH relative to ambient; VPD≈0.8kPa). The stem diameter increment, assimilation rate (A ), and E were highest, and the needle-to-fine root biomass ratio was smallest in 'highT/lowRH' treatment (P A of trees grown in organic soil was higher (P <0.05) in 'highT/lowRH' treatment compared to ambient conditions, but no significant difference was found in mineral soil. Our findings indicate that the effect of a 3-°C temperature increase on spruce was marginal under well-watered conditions, and moderate VPD increase instead improved the tree's functioning. Thus, aside from temperature, the impact of the RH as a primary driver of the VPD should be considered when predicting spruce response to global warming.

The response of leaf traits and photosynthetic characteristics to selenium (Se) application reflects plant adaptation strategies for selenium-enhanced accumulation of photosynthetic products. This study selected eggplant as the research subject and conducted a field experiment to better understand these relationships. This study included three Se treatments, foliar sprays of 0.5mgL-1 (T1), 1mgL-1 (T2), and 1.5mgL-1 (T3), with tap water as the control (CK). The results revealed that T1 and T2 significantly improved leaf traits and photosynthetic characteristics compared to CK, while T3 had a negative effect. Regarding the leaf area-leaf thickness (LA-LT) trade-off relationship, the T2 treatment favoured LA, whereas the CK, T1, and T3 treatments favoured LT, with trade-off values of T3>T1>CK. Regarding the net photosynthetic rate-transpiration rate (Pn -Tr ) trade-off relationship, the CK treatment favoured Tr , whereas the T1, T2, and T3 treatments favoured Pn , with trade-off values of T2>T1>T3. In T1 and T2, the eggplant specific leaf area and Pn showed non-significant and highly significant positive correlations, respectively, and in CK and T3 showed non-significant and highly significant negative correlations, respectively. These results indicate that foliar application of Se at appropriate concentrations can increase crop productivity in semi-arid areas.

Drying wheat (Triticum durum ) seeds within their spikes may improve the seed desiccation tolerance. This study aimed to understand the effect of drying wheat seeds within their spikes on their desiccation tolerance in association with GABA (γ-aminobutyric acid) content, malondialdehyde (MDA), the expression of three dehydrin genes (dhn , wcor , dreb ) during seed development. Seeds of wheat variety 'Hourani-Nawawi' were harvested at five developmental stages: (1) milk (ML); (2) soft dough (SD); (3) hard dough (HD); (4) physiological maturity (PM); and (5) harvest maturity (HM) and dried either attached to or detached from their spikes. Drying the seeds attached to their spikes improved desiccation tolerance, speed of germination, and seedling length at ML stage. Before drying (freshly harvested), the seeds harvested at ML and HM had higher GABA than those at SD, HD, and PM. The attached-dried seeds had higher GABA content from ML to PM than at HM, and higher glutamate content at ML, SD, and HD than at the PM stage. Detached-dried seeds had the highest alanine at ML and PM. Attached-dried seeds had lower MDA than detached-dried seeds. Expression of dhn was highest in freshly-harvested and attached-dried seeds at SD. Highest expression of wcor in the attached-dried seeds was detected at SD and HM. Drying the seeds within their spikes increased the expression of dreb gene compared with the freshly-harvested seeds, except at the HD stage. In conclusion, drying the seeds within their spikes enhanced seed germination in association with higher GABA, lower MDA, and higher gene expression.

Rice (Oryza sativa ) is a crucial staple crop worldwide, providing nutrition to more than half of the global population. Nonetheless, the sustainability of grain production is increasingly jeopardized by both biotic and abiotic stressors exacerbated by climate change, which increases the crop's rvulnerability to pests and diseases. Genome-editing by clustered regularly interspaced short palindromic repeats and CRISPR-associated Protein 9 (CRISPR-Cas9) presents a potential solution for enhancing rice productivity and resilience under climatic stress. This technology can alter a plant's genetic components without the introduction of foreign DNA or genes. It has become one of the most extensively used approaches for discovering new gene functions and creating novel varieties that exhibit a higher tolerance to both abiotic and biotic stresses, herbicide resistance, and improved yield production. This study examines numerous CRISPR-Cas9-based genome-editing techniques for gene knockout, gene knock-in, multiplexing for simultaneous disruption of multiple genes, base-editing, and prime-editing. This review elucidates the application of genome-editing technologies to enhance rice production by directly targeting yield-related genes or indirectly modulating numerous abiotic and biotic stress-responsive genes. We highlight the need to integrate genetic advancements with conventional and advanced agricultural methods to create rice varieties that are resilient to stresses, thereby safeguarding food security and promoting agricultural sustainability amid climatic concerns.

Detrimental effects of terminal heat stress could be mitigated by exogenous application of synthetic compounds by preserving cell membrane integrity and protecting against oxidative damage. A field experiment was conducted to test the application of seven synthetic compounds on wheat growth traits: (1) thiourea (20 mM and 40mM); (2) potassium nitrate (1% and 2%); (3) sodium nitroprusside (400 μg mL-1 and 800μg mL-1 ); (4) dithiothreitol (25 ppm and 50ppm); (5) salicylic acid (100 ppm and 200ppm); (6) thioglycolic acid (200 ppm and 500ppm); and (7) putrescine (4 mM and 6mM). These compounds were applied at the anthesis and grain-filling stages to enhance physio-biochemical traits and yield attributes of wheat (Triticum aestivum ) cvs GW-11 and GW-496 under terminal heat stress. The results indicated that GW-11 plants treated with 100ppm salicylic acid exhibited significant improvements (P ≤0.05) in canopy temperature depression, proline content, total chlorophyll content, and the membrane stability index. Compared with the control treatment, foliar application of 100ppm salicylic acid at both stages caused increases in grain yield (19.5%), followed by a 14% increase with 4mM putrescine. These yield improvements were attributed to higher grains per spike, more effective tillers, and greater 1000-grain weight, reflecting enhanced sink capacity and grain development under stress. Consequently, the foliage application of 100ppm salicylic acid at the anthesis and grain-filling stages is recommended to improve late-sown wheat productivity and reduce terminal heat stress.

Climate change is leading to increased heavy rainfall, making plant submergence in flood-prone pastures more common. Forage legumes play a vital role in boosting herbage production and quality, especially when grown with grasses in low nitrogen input areas. However, their tolerance to complete submergence and subsequent recovery remains poorly understood. This study evaluated eight forage legumes after 5 or 10 days of complete submergence: (1)Lotus tenuis; (2) Lotus corniculatus; (3) Lotus japonicus; (4) Trifolium repens; (5) Trifolium fragiferum; (6) Trifolium pratense; (7) Trifolium michelianum; and (8) Melilotus albus. We assessed physiological and growth traits related to tolerance and recovery. All species survived except M. albus and T. michelianum. For the six surviving species, growth parameters linked to recovery were more prominent in Lotus species than in Trifolium species. Lotus species maintained higher biomass, improved stomatal conductance, and increased chlorophyll concentration in young leaves, along with a quicker recovery of PSII efficiency. In contrast, T. pratense showed the least tolerance and recovery, indicating its unsuitability for waterlogged areas. L. tenuis emerged as the most promising species for submergence tolerance, with L. corniculatus also showing potential, particularly in areas prone to short-term flooding.

Remote sensing of stressor action on plants is an important step of their protection. Measurement of photochemical reflectance index (PRI) can be used to detect action of stressors including salinization; potentially, a small-scale spatial heterogeneity of PRI (within leaf or its part) can be an indicator of this action. The current work was devoted to analysis of sensitivity of the small-scale heterogeneity in PRI and in the reflected light intensity at 530nm (approximately corresponding to the measuring wavelength for PRI) in leaves of pea (Pisum sativum ) plants to action of salinization. Plants were cultivated under controlled conditions of a vegetation room and under open-air conditions. It was shown that both the standard deviation of PRI and coefficient of variation of the reflected light intensity at 530nm were sensitive to action of salinization on plants. Moreover, this variation coefficient was negatively corelated to the potential quantum yield of PSII; i.e. increasing the coefficient could be used to estimate decreasing this yield caused by photodamage of PSII under salinization. Our results show that the small-scale spatial heterogeneity in PRI and the reflected light intensity at 530nm can be used as additional tools of the remote sensing of plant responses under action of salinization.