Hasil untuk "Botany"

L. M. Perry, J. Metzger

J. Willis

P. Bosland, E. Votava

W. Maddison, R. FitzJohn

Byron Vaughn, R. Ligrone, H. Owen et al.

M. Boudreau, F. Beland

M. Ayyanar, P. Subash-Babu

B. Freeman, J. Lee‐Yaw, J. Sunday et al.

1Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada 2Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada 3Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada 4School of Marine and Environmental Affairs, University of Washington, Seattle 5Department of Biology, McGill University, Montreal, Quebec, Canada

V. Lebot

Sonam Sonam, Shaubhik Anand, Nidhi Pareek et al.

Soda lakes are ecologically significant habitats characterized by high salinity, alkaline pH, and intense evaporation. These milieus are hostile to most life, though these lakes could be a rich source for discovering novel halotolerant and halophilic cyanobacterial taxa. The Indian subcontinent is endowed with shallow saline–alkaline lakes whose cyanobacterial diversity has been little explored. The present study was undertaken to explore the cyanobacterial diversity in an inland saline–alkaline lake (Sambhar Lake) in India using a polyphasic approach. Two thin, filamentous strains encapsulated within thick sheaths and capable of nodule formation under normal light conditions were recovered. Both isolates exhibited growth at up to 4% salinity, indicating their halotolerant nature. The studied strains exhibited <95% 16S rRNA gene similarity with closely related taxa from the genera <i>Thainema</i> and <i>Insularia</i> and formed a distinct evolutionary lineage in phylogenetic tree supported by a high bootstrap value. Additionally, the secondary structures of the 16S-23S Internal Transcribed Spacer (ITS) regions (D1-D1′ and BoxB) of the studied strains showed remarkable differences from phylogenetically closely related taxa, indicating these strains represent a new genus in the Nodosilineales: <i>Krienitziella sambharensis</i> gen. et sp. nov., in accordance with the International Code of Nomenclature for Algae, Fungi, and Plants (ICN).

Ofir Katz, Ofir Katz, Mikhail S. Blinnikov et al.

Masoomeh Zaboli, Fatemeh Nejad-Alimoradi, Fatemeh Rostami et al.

Abstract Background Poa pratensis L. is a perennial grass commonly used for ecological restoration due to its rapid growth rate and strong adaptability. It is considered an excellent choice for soccer fields and urban green spaces because of its high wear resistance and durability. this is the first report demonstrating the co-application of seed priming and plasma-activated water irrigation for enhancing drought resistance in P. pratensis. This study aimed to examine the influence of seed priming and irrigation with PAW on the growth of P. pratensis and its ability to endure drought conditions. The experiment was conducted in a greenhouse in 2023, using a completely randomized design. Seeds were primed with either normal water (control group) or PAW and then sown in pots containing standard soil. The experiment included six treatments: three PAW management strategies—watered normally (WW, control group), seeds primed with PAW and irrigated with normal water (PW), and a combination of both methods (PP: primed and irrigated with PAW)—under both drought and non-drought stress conditions. Results The findings indicated that drought stress significantly decreased various growth parameters, including fresh weight (21% reduction), dry weight (27% reduction), chlorophyll levels (12% reduction), and the activities of the enzymes ascorbate peroxidase (APX) and catalase (CAT) (22% and 5% reductions, respectively) in P. pratensis. Conversely, drought stress increased the levels of several compounds: carotenoids (24% increase), malondialdehyde (MDA) (81% increase), proline (80% increase), soluble carbohydrates (15% increase), and the enzyme activity of guaiacol peroxidase (GPX) (36% increase). Under drought conditions, seed priming with PAW led to a decrease in MDA (21%) and an increase in fresh weight (approximately 13%) and dry weight (about 25%). Total chlorophyll increased by around 30%, while proline and soluble sugar content rose by 14% and 50%, respectively. The activities of APX, CAT, and GPX enzymes increased by 18%, 4%, and 11%, respectively. In summary, the combination of seed priming and irrigation with PAW under drought conditions reduced MDA content by 28% and enhanced plant biomass (fresh weight by 13% and dry weight by 21%), photosynthetic pigments (total chlorophyll by 17%), and osmoprotectants (proline by 56% and soluble carbohydrates by 11%). The activities of APX, CAT, and GPX also increased significantly—by 16%, 2%, and 16%, respectively. Conclusions PAW has been shown to improve drought stress in P. pratensis by reducing lipid peroxidation and increasing levels of photosynthetic pigments, osmoprotectants, and antioxidant enzyme activity. The results indicate that the most beneficial outcomes occur when seed priming is combined with PAW irrigation. This technology could serve as a cost-effective and sustainable method for enhancing growth and drought tolerance in plants, including P. pratensis, under water-stressed conditions. Further studies are necessary to explore this effect on additional plants and to better understand its details and possible mechanisms in future research.

Eric Prendes-Rodríguez, Alicia Iborra, Carla Guijarro-Real et al.

Cauliflower landraces (<i>Brassica oleracea</i> var. <i>botrytis</i>) safeguard allelic diversity for adaptation, yet their phenotypic breadth under winter field conditions remains under-documented. We evaluated 69 Spanish landraces and two commercial checks from the COMAV-UPV genebank using 15 quantitative and 21 qualitative descriptors. Seed viability ranged from 0 to 92%, and mature plants showed wide ranges in stem length (coefficient of variation ≈ 72%), leaf size, and head weight (100–723 g). Six curd-colour classes—including uncommon purple and Romanesco green—were recorded. Most accessions (>88%) required more than 120 days from sowing to harvest, but a distinct subset (12%) matured within 60–120 days. Plant stature tended to be positively associated with head mass, whereas highly branched inflorescences matured earlier. Variation was dominated by curd size and plant architecture. Multivariate analyses—principal component analysis for quantitative traits, multiple correspondence analysis for qualitative traits, factor analysis of mixed data, and clustering of FAMD scores by k-means—resolved three phenotypic clusters spanning a gradient of curd size/architecture and plant stature. The collection includes accessions with compact curds, earliness, or distinctive pigmentation that are immediately useful for breeding and for prioritizing regeneration. These results provide a phenotypic baseline for future genomic association studies and the development of cultivars adapted to winter production.

Angelika Till, Silvia Ulrich, David J. Cantrill et al.

Until now investigations on the ultrastructural characteristics of <i>Pseudanthus</i> pollen using transmission electron microscopy (TEM) were limited. The aims of this study were as follows: (1) to present the first comprehensive TEM-based analysis of <i>Pseudanthus</i> pollen; (2) to provide a holistic morphological and ultrastructural description of <i>Pseudanthus</i> pollen; (3) to compare <i>Pseudanthus</i> pollen to that from other Picrodendraceae and closely related families; (4) to clarify intraspecific, interspecific, intrafamilial, and interfamilial character traits of <i>Pseudanthus</i> pollen in relation to that from related genera/families; and (5) to conclude if <i>Pseudanthus</i> pollen could potentially be identified in the palynological record. <i>Pseudanthus</i> pollen samples were collected from anthetic flowers and prepared according to standard methods for investigation with TEM. Interpretations of pollen ultrastructure in other Picrodendraceae and closely related families were based on previously published TEM micrographs. The pollen ultrastructure from six out of nine <i>Pseudanthus</i> species is described here for the first time. By integrating LM, SEM, and TEM techniques, this study offers a holistic perspective on the genus’s pollen morphology and ultrastructural range. It also illuminates the intraspecific and interspecific pollen morphological and ultrastructural diversity within <i>Pseudanthus</i> and how it differentiates from other Picrodendraceae as well as the Euphorbiaceae and Phyllanthaceae. The combined morphological and ultrastructural traits of <i>Pseudanthus</i> pollen render it unique among Picrodendraceae and differentiate it from the pollen of closely related families. This opens the door for future paleopalynological investigations, but until now <i>Pseudanthus</i> pollen has not been reported from the fossil record.

K. Hyde, C. Norphanphoun, J. Ma et al.

CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, Yunnan 650201, P.R. China Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand Mushroom Research Foundation, 128 M.3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Mai 50150, Thailand School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, P.R. China Center for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, Honghe County, Yunnan 654400, P.R. China Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China College of Agriculture, Key Laboratory of Agricultural Microbiology of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025, P.R. China Department of Botany and Microbiology, College of Science, King Saud University, Saudi Arabia Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, P.R. China Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand Engineering and Research Center for Southwest Biopharmaceutical Resource of National Education Ministry of China, Guizhou University, Guiyang, Guizhou 550025, P.R. China Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan 671003, P.R. China National Institute of Fundamental Studies (NIFS), Hantana Road, Kandy, Sri Lanka School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, Guizhou 550003, P.R. China Yunnan Key Laboratory of Fungal Diversity and Green Development, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, P.R. China

Zanwen Zuo, Zerong Zhou, Yuzhou Chang et al.

Ribonucleotide reductase M2 (RRM2) is a small subunit in ribonucleotide reductases, which participate in nucleotide metabolism and catalyze the conversion of nucleotides to deoxynucleotides, maintaining the dNTP pools for DNA biosynthesis, repair, and replication. RRM2 performs a critical role in the malignant biological behaviors of cancers. The structure, regulation, and function of RRM2 and its inhibitors were discussed. RRM2 gene can produce two transcripts encoding the same ORF. RRM2 expression is regulated at multiple levels during the processes from transcription to translation. Moreover, this gene is associated with resistance, regulated cell death, and tumor immunity. In order to develop and design inhibitors of RRM2, appropriate strategies can be adopted based on different mechanisms. Thus, a greater appreciation of the characteristics of RRM2 is a benefit for understanding tumorigenesis, resistance in cancer, and tumor microenvironment. Moreover, RRM2-targeted therapy will be more attention in future therapeutic approaches for enhancement of treatment effects and amelioration of the dismal prognosis.

Shashi Bhushan, Amit Kumar Singh, Yogendra Thakur et al.

Abstract In the model plant Arabidopsis thaliana, parental age is known to affect somatic mutation rates in their immediate progeny and here we show that this age dependent effect persists across successive generations. Using a set of detector lines carrying the mutated uidA gene, we examined if a particular parental age maintained across five consecutive generations affected the rates of base substitution (BSR), intrachromosomal recombination (ICR), frameshift mutation (FS), and transposition. The frequency of functional GUS reversions were assessed in seedlings as a function of identical/different parental ages across generations. In the context of a fixed parental age, BSR/ICR rates were unaffected in the first three generations, then dropped significantly in the 4th and increased in most instances in the 5th generation (e.g. BSR (F1 38 = 0.9, F2 38 = 1.14, F3 38 = 1.02, F4 38 = 0.5, F5 38 = 0.76)). On the other hand, with advancing parental ages, BSR/ICR rates remained high in the first two/three generations, with a striking resemblance in the pattern of mutation rates (BSR (F1 38 = 0.9, F1 43 = 0.53, F1 48 = 0.79, F1 53 = 0.83 and F2 38 = 1.14, F2 43 = 0.57, F2 48 = 0.64, F2 53 = 0.94). We adopted a novel approach of identifying and tagging flowers pollinated on a particular day, thereby avoiding biases due to potential emasculation induced stress responses. Our results suggest a time component in counting the number of generations a plant has passed through self-fertilization at a particular age in determining the somatic mutation rates.

Krešimir Dvojković, Ivana Plavšin, Dario Novoselović et al.

Extended drought affects the production and quality of wheat (<i>Triticum aestivum</i> L.), one of the world’s most important food crops. Breeding for increased drought resistance is becoming increasingly important due to the rising demand for food production. Four old traditional Croatian wheat cultivars were used in the present study to examine the early antioxidant response of flag leaves to desiccant-stimulated drought stress and to identify drought-tolerant cultivars accordingly. The results indicate that the enzymatic antioxidant system plays the most significant role in the early response of adult wheat plants to drought stress and the removal of excessive H₂O₂, particularly GPOD and APX. Nada and Dubrava cultivars revealed the strongest activation of the enzymatic defense mechanism, which prevented H₂O₂ accumulation and lipid peroxidation. Additionally, the Nada cultivar also showed increased synthesis of proline and specific phenolic compounds, which both contribute to the increased stress tolerance. Among the cultivars investigated, cultivar Nada has the broadest genetic base, which may explain why it possesses the ability to activate both enzymatic and non-enzymatic defense mechanisms in an early response to drought stress. This suggests that old traditional wheat cultivars with broad genetic bases can be a valuable source of drought tolerance, which is especially important given the current climate change.

Вероника Борисовна Багмет, Шамиль Раисович Абдуллин

Изучение флоры с помощью световой и сканирующей электронной микроскопии позволило получить данные о новых для России и региона видах Bacillariophyta из некоторых временных водоемов острова Сахалин. Всего выявлено 26 новых и редких таксонов. Из них 14 видов оказались новыми для флоры острова Сахалин, 7 – для Российского Дальнего Востока, 3 (Gomphonema procerum, Hannaea yalaensis, Pinnularia saga) – для флоры России. В ходе работы обнаружены таксоны Placoneis sp. и Ulnaria sp., которые, возможно, являются новыми для науки, так как их морфологические и морфометрические характеристики отличаются от ранее описанных видов.

N. V. Kishlyan, N. V. Melnikova, T. A. Rozhmina

Excessive soil acidity is one of the main factors causing significant losses in crop production. Using fiber flax, the effect of soil acidity on the yield and fiber quality of various samples representing the world gene pool of this crop is shown. The optimum acidity for fiber flax is within a narrow range – pHKCl 5.3–5.6. On strongly acid soils (pHKCl less than 4.5) with threshold values of the toxic aluminum (Al3+) content, 10–11 mg/100 g, a decrease in the flax yield is over 50%. Currently, along with the mechanisms of detoxification of toxic aluminum in acid soils, genetic aspects of aluminum resistance have also been determined. It is shown that one of the most significant components of the common defense response of plants to various stresses is their antioxidant systems. An important role in the antioxidant defense system belongs to glutathione transferases. Using high-through put sequencing and quantitative PCR, a change in the expression of genes and microRNAs in flax plants was revealed in response to the toxic effect of aluminum ions. Using flax genotypes contrasting in acid resistance, an increase in the expression of genes encoding UDP-glycosyltransferases (UGT) and glutathione-S-transferases (GST) was established under aluminum stress. The increase in expression was more pronounced in aluminum-resistant flax cultivars than in sensitive ones. Also, the differences in the change of miR390 and miR393 expression between resistant and sensitive genotypes were revealed under the toxic effects of aluminum ions. Understanding the resistance mechanisms makes it possible to accelerate the development of flax and other crop cultivars adaptive to edaphic stress, which is important for obtaining high and guaranteed yields of agricultural products.