Acta Physiologiae Plantarum最新文献

As a crucial oil crop, sunflower (Helianthus annuus L.) has a high content of unsaturated fatty acids (FAs). The unsaturated FAs found in sunflower oil mainly include oleic acid (OA, C18:1) and linoleic acid (LOA, C18:2). OA’s antioxidant activity makes sunflower oil with high health value and suitable for storage. However, molecular mechanisms underlying differences in OA accumulation between high- and low-oleate sunflower varieties in seed development remain unexplored. Here, to identify key OA synthesis-related proteins, isobaric tag for relative and absolute quantitation (iTRAQ) was performed. Ultimately, 592 differentially expressed proteins (DEPs) (233 upregulated, 359 downregulated) were identified between high-oleate (‘L-1-OL-1’) and low-oleate (‘86–1’) maintainer lines. KEGG enrichment analysis of DEPs identified biosynthesis of unsaturated FAs as the most highly enriched biological pathway. Subsequently, combined transcriptome and proteome analysis results suggested that several proteins in this pathway might influence final seed OA content, including FAD2 (Δ12 fatty acid desaturase). Notably, FAD2 expression was significantly downregulated in ‘L-1-OL-1’ versus ‘86–1’ seeds, with results aligning with FAD2 mRNA expression results determined via qRT-PCR analysis. These findings and understanding of OA synthesis mechanisms could help improve oil quality through breeding and germplasm-based efforts in sunflower.

In the present study, a comparative study involving soybean (Glycine max L.) seeds- (SPE) and sprouts-extract (SSE) as a pre-conditioning media was performed to evaluate their allelopathic impact on nodding broomrape (Orobanche cernua L.) germination. Contrasting germination behaviour of broomrape, characterised by respective inhibition and induction in its germination was observed in response to an optimised concentration of SPE and SSE. Further study was conducted to explore the phyto-constituents of soybean seed- (SSP) and sprout-flour (SSF) responsible for differential germination of broomrape. Plant-growth regulators quantification revealed a relative enhanced bioactive gibberellin (GA₄) to abscisic acid (ABA) ratio (GA₄: ABA) in SSF. Carbohydrates analysis revealed a relative reduced content of soluble-sugars, starch, sucrose (SUC) and raffinose-family oligosaccharides (RFOs) in concomitant with relative enhanced levels of reducing-sugars, glucose (GLU) and galactose (GAL) in SSF. The isoflavone content (IFC) analysis revealed a relative enhanced level of total IFC and individual bioactive aglycones [viz. daidzein, glycitein and genistein (GEN)] in SSF. Exogenous applications of GA₃, ABA and its antagonists (viz. uniconazole and fluridone), mono- (viz. GLU and GAL), oligo-saccharides (viz. SUC and RFOs), SPE₅₀ and SSE₅₀ pre-treated with enzyme-mix harbouring RFOs- and SUC-metabolizing enzymes (viz. α-galactosidase + invertase) and GEN as a pre-conditioning media of broomrape were also in agreement with the aforesaid observations. To the best of our knowledge, this is first report mentioning the contrasting germination behavior of broomrape towards SPE and SSE. Overall, these findings could be explored to formulate the ‘Green’ methods for the control of parasitic-weed infestation in agonomically important crops.

Heavy metal stress destroys plants growth and yield. Glutathione (GSH) is a well-known antioxidant that promotes plant growth by protecting it from abiotic stresses including heavy metal toxicity. Although much has been documented about the role of glutathione in securing plants from stress, its role in safeguarding wheat growth under mercury (Hg) and arsenic (As) stresses is unknown. The present work investigates wheat responses to Hg and As stresses under the exogenous application of GSH. The result showed that Hg and As stresses greatly reduced seed germination and seedling growth such as root/shoot length and fresh weight. Photosynthetic pigments, i.e., chlorophyll a, b, and carotenoid were reduced. However, the H₂O₂ and lipid peroxidation levels were increased under Hg and As stresses in wheat seedlings. The antioxidant enzymatic activities such SOD, POD, and APX increased, while CAT activity decreased under Hg and As stresses. Importantly, the application of 2 mM GSH alone or in combination with Hg and As enhanced seed germination rate, root/shoot length, fresh weight, and photosynthetic pigments in wheat. Contrarily, the level of H₂O₂ and lipid peroxidation were decreased under the individual and combined treatment of Hg + GSH and As + GSH. The antioxidant enzymatic activities such as SOD, POD, and APX were lowered, while CAT activity was enhanced by GSH under Hg and As stress. The present research concludes that supplementation of exogenous GSH can play a significant role in fostering the sensitivity of wheat to Hg and As stress by reducing oxidative stress and modulating the levels of antioxidant enzymes.

Priming in plants enables them to store information and better prepare for future stress. This study tested the hypothesis that priming rice plants (cv. BRS AG) improves sugar metabolism and transport in the grain-filling stage through memory effects. We investigated physiological changes, including source–sink parameters, carbohydrate metabolism, gene expression, and vascular adjustments. Rice plants were exposed to 150 mM salt stress during either the V5 vegetative and/or R7–R8 reproductive stages, with samples collected after 7 days of stress and after 2 days of recovery. Our findings reveal that primed plants had a more favorable Na⁺/K⁺ ratio in roots, experienced less leaf stress, and showed increased phloem area and reduced metaxylem area under salt stress. Notably, primed plants maintained stable plant height and shoot dry mass during the grain-filling stage. These results support the hypothesis that salt priming in the vegetative stage alters the responses to subsequent salt exposure, improving ionic homeostasis and sucrose transport, which mitigates salt-stress effects. Priming also influenced the expansion of conducting vessels in leaves and roots, contributing to shoot growth. Enhanced vascular characteristics and the regulation of sucrose and triose-phosphate transporters likely facilitated better carbohydrate remobilization to develop grain production potential. These insights into salt stress memory mechanisms highlight strategies to improve rice yield under challenging environmental conditions.

Citrus is a globally grown fruit crop because of the nutritional benefits. Climate change drastically affects plant physiology, morphology, and anatomy. Physiological alterations within plants allow them to adapt to changing environments, however, the degree and quantification of these modifications differs with varieties. Ten exotic and local citrus rootstocks were evaluated based on morphology, physiology, and anatomical response to different heat stress conditions to identify best suitable rootstocks in climate change scenarios. Brazilian sour orange and Gadha dahi showed heat stress tolerance through maintaining plant growth, retention of root and shoot moisture contents, higher photosynthetic pigments and leaf water potential. Higher moisture contents of root and shoot were recorded (66.00 ± 1.1% and 73.00 ± 0.94%) in Brazilian sour orange at moderate levels of stress respectively. Which significantly reduces in Rangpur poona nucellar to (33.33 ± 0.6% and 32.67 ± 1.45%) when the level of stress was intensified. Under moderate and severe stress conditions the lowest chlorophyll a content was recorded in Kirrumakki nucellar (2.20 ± 0.05 mg/g) and Brazilian sour orange (1.32 ± 0.05 mg/g) respectively, due to reduced photosynthetic pigment, thylakoid membrane damage and alteration of chloroplast. Higher H₂O₂ and proline production were indication of tolerant rootstock to heat stress in Brazilian sour orange and Gadha dahi. Two highly tolerant (Brazilian sour orange and Gadha dahi) and two highly sensitive rootstocks (Rangpur poona nucellar and Sunki Bentake) from the experiment were selected for stem and leaf anatomical observations. Brazilian sour orange under heat stress was characterized with thicker cell epidermis which reduce the transpiration and evaporation losses in addition to having higher vascular bundle, xylem, and phloem length. These anatomical modifications ensured the transport of water and nutrients across the plant body which helped in maintaining plant vigor and growth. This study provides valuable knowledge in tolerant citrus rootstock to mitigate global warming.

Light (spectrum, intensity, photoperiod) is one of the most important factors that governs the proliferation of many plant species cultured in vitro. In this study, the in vitro shoot proliferation, photosynthetic pigments, photosystem II photochemistry, and leaf anatomy of the GF677 rootstock (Prunus persica x Prunus amygdalus) were investigated under three light intensities (20, 40 and 120 μmol m⁻² s⁻¹) provided by light-emitting diode (LED) lamps with a 430–690 nm absorption spectrum, emitted mainly by blue (21%) and red (63%) (BR, 1:3). The culture medium used was the MS supplemented with 3.1 μM benzyl adenine, 0.05 μM α-naphthalene acetic acid, 0.3 μM gibberellic acid, 20 g L⁻¹ sucrose (pH .8), and 6 g L⁻¹ Plant Agar (30 days, 16h photoperiod, 22 ± 2 °C). The results showed that shoot multiplication percentages (90.48–92.86%), proliferation rates (new shoots per explant) (1.95–2.10), shoot height (0.52 cm), maximum efficiency of photosystem II (PSII) photochemistry (F_v/F_m), and the efficiency of excitation energy capture by open PSII reaction centers (F_v′/F_m′) were significantly higher under 20 μmol m⁻² s⁻¹ and 40 μmol m⁻² s⁻¹ as compared to 120 μmol m⁻² s⁻¹. Moreover, under 20 μmol m⁻² s⁻¹, the photoprotective energy dissipation (Φ_NPQ), the quantum yield of non-regulated energy loss in PSII (Φ_NO), chlorophyll b (Chl b), total chlorophyll (a + b), and carotenoids were enhanced as compared to 40 μmol m⁻² s⁻¹, whereas the percentage of explants with macroscopically stress appearance symptoms (23.21%) and chlorophyll a/chlorophyll b (Chl a/Chl b) ratio were significantly lower under 20 μmol m⁻² s⁻¹. Leaves grown under 20 μmol m⁻² s⁻¹ exhibited a somehow typical dorsiventral leaf anatomy with distinguishable palisade and spongy parenchyma with more layers of palisade parenchyma as compared to the produced thin leaves with suppressed mesophyll tissue under 40 μmol m⁻² s⁻¹. Based on the results obtained, among the three different intensities tested, 20 μmol m⁻² s⁻¹ is the best and most beneficial lighting condition for GF677 proliferation.

Previous studies reported that plants’ exposure to particulate matter (PM) may decrease the PM phytoremediation efficiency. This study aims to investigate the effect of PM on plants at the proteomic level. Here, five plant species were fumigated with cigarette PM (the initial PM_2.5 of 470–500 µg/m³) in a 15.6 L testing chamber for 6 days. PM removal efficiency and absorption were evaluated for protein pattern between plants exposed and non-exposure to PM for 24 h. The results showed that Z. zamiifolia and S. trifasciata can effectively remove indoor PM (35–40 μg/m³). Also, several plant proteins (heat shock, aconitate hydratase 3, chaperone protein, NADP-dependent malic enzyme, probably aquaporin TIP2-2, serine hydroxymethyltransferase 2, ATP-dependent zinc metalloprotease FTSH 8, V-type proton ATPase subunit B2, malate dehydrogenase, peptidyl-prolyl cis–trans isomerase, CYP38, peroxiredoxin-2E, and histone) reported significantly upregulated and downregulated about 100 times after PM exposure than control. Proteins related to water accumulation and H₂O₂ scavenging significantly changed (p value < 0.05) after PM exposure. PM concentration was found low (< 0.5 mg/m²) on the leaf surface after 150 h exposure. Herein, water accumulation and H₂O₂ scavenging protein might play an important role in plant PM stress.

Flax (Linum usitatissimum L.) phloem fibers produce a tertiary cell wall as part of regular plant growth. The fiber tertiary cell wall is responsible for supporting the stem’s vertical position and is involved in the implementation of the negative gravitropic reaction when it is tilted. Rhamnogalacturonan I (RG-I) is one of the main matrix polysaccharides of the tertiary cell wall, playing an essential role in its functioning. The distribution of RG-I in fibers isolated from two stem sides (pulling and opposite) during graviresponse was studied. The increased content of galactose-containing polymers in the cell walls of fibers from the pulling stem sides was demonstrated. Differences in the distribution of RG-I epitopes on different sides of the stem were shown. RG-I with branched galactan side chains was found in the fiber tertiary cell walls; the labeling of such side chains in the cell wall of fibers from the pulling side of the stem was increased during gravistimulation. Using transcriptome analysis, the upregulation of genes encoding enzymes involved in RG-I metabolism (synthesis and modifications) in the fibers from the pulling stem side, mainly at the early stage of graviresponse, was revealed. A special role for fasciclin-like arabinogalactan proteins in response to mechanical stimuli was proposed. For the purpose of further modifying the plant cell wall properties, it would be worthwhile to have an understanding of the processes taking place in the fiber cell wall, both in normal conditions and during mechanical stress.

Plant of Lycium barbarum L., in Chinese name of “Goqi” tree, produce very important traditional Chinese medicine of Goqi berries for clinical application over 2000 years in China. In the early stage, people conducted extensive research on the bioactive components, planting methods, and deep processing of L. barbarum L., yet paid scant attention to the rhizosphere microorganisms surrounding their roots. In this context, the rhizosphere soil of L. barbarum L., collected in Ningxia province of China, was studied to investigate the microbial diversity by performing 16S rRNA/ITS sequencing, which led to identify 29 strains including 9 bacteria and 20 fungi. On the bases of the GNPS analysis of HPLC-q-ToF MS data of the fermentation broth, rich secondary metabolites were identified from twenty microorganisms. The molecular network clustering analysis suggests that the fermentation broth of bacteria may contain 607 compounds and that of fungi may contain 1359 compounds, involving multiple types. Antibacterial activity evaluation results revealed that rhizosphere microorganisms had inhibitory effects on Staphylococcus aureus and Candida albicans. This article lays a scientific foundation for the utilization of soil biological resources in L. barbarum L. cultivation and paves the way for the discovery of novel antibacterial active substances with unique structures.

The occurrence of control failure after herbicide application suggests the emergence of tolerant D. nuda in sugarcane crops. However, the presence of species within the herbicide-resistant weed community before the selection process can be partially attributed to ecological adaptability. Biological studies of Digitaria spp. in areas without resistance reports are essential to understand the initial characteristics of populations before resistance events. In the present study, the predominance of Digitaria species was evaluated in ten areas of sugarcane cultivation without records of populations resistant to photosystem II-inhibiting herbicides belonging to four mills. First, we determined the sensitivity of Digitaria populations to herbicides. In addition, interspecific competitiveness and growth under nutrient and water availability conditions were determined for each identified species of Digitaria. The survey revealed a predominance of D. horizontalis and D. nuda in populations composed of D. bicornis and D. ciliaris, and all them were susceptible to herbicides. The combinations of competition between species showed no significant differences. D. nuda has a greater increase of aboveground biomass under water availability, which may favor its adaptation in areas with sugarcane straw left on the soil. The predominance of susceptible D. nuda in some populations is primarily due to its biological characteristics and its adaptation to cultivation practices. However, D. nuda plants obtained from the two susceptible populations showed differential responses to diuron, indicating diversity in populations in terms of herbicide response.