scholarly journals The Roles of Cytokinins in Plants and Their Response to Environmental Stimuli

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1158
Author(s):  
R. J. Neil Emery ◽  
Anna Kisiala
Keyword(s):  
Plant Growth ◽  
Pathogenic Bacteria ◽  
Signaling Molecules ◽  
Photosynthetic Performance ◽  
Plant Responses ◽  
Plant Metabolism ◽  
Plant Interactions ◽  
Environmental Stimuli ◽  
Open Questions ◽  
Almost All

Cytokinins (CKs) are adenine-derived, small-molecule plant growth regulators that control aspects of almost all plant growth and development processes. Internally, CKs play significant roles in plant cell division, nutrient allocation, and photosynthetic performance, and they are also detection and signaling agents for plant responses to the environmental challenges. CK functions in plant metabolism include plant adaptations to various abiotic stresses as well as their regulatory role in plant interactions with biotic components of the environment. Interestingly, CK biosynthesis is not exclusive to plants. New genetic and chemical approaches have revealed that both beneficial (symbiotic microorganisms) and detrimental (pathogenic bacteria, fungi, or insects) non-plant biota can secrete these phytohormones to purposefully modify plant metabolism. Therefore, while many open questions remain about how CKs are actively utilized by plants and plant-interacting organisms, CK roles should be seen more broadly, as signaling molecules for which effects range from within cells to as far as interkingdom relationships. The papers in this Special Issue highlight several aspects of CK biosynthesis, metabolism, and functions within plants and among plant-associated organisms, typifying the extensive range of roles played by these signaling molecules. The collection of papers represents new examples for CK researchers to consider advancing the growing range of topics related to how CKs mediate responses to many kinds of environmental stimuli and stresses.

Potential Role of Endophytes for Sustainable Environment

2019 ◽  
pp. 78-95
Author(s):  
Zubair A. Dar ◽  
Bhat Rifat ◽  
Javeed I. A. Bhat ◽  
Asma Absar Bhatti ◽  
Shamsul Haq ◽  
...  
Keyword(s):  
Plant Growth ◽  
Organic Contaminants ◽  
Plant Stress ◽  
Plant Responses ◽  
Sustainable Environment ◽  
Plant Growth Promoting ◽  
Plant Stress Tolerance ◽  
Growth Promoting ◽  
Almost All

Endophytes are symptomless fungal and bacterial microorganisms found in almost all living plants. They are vital components of plant microbiomes. Endophytes affect plant growth and plant responses to pathogens, herbivores, and environmental change by producing a range of natural products having antifungal, antibacterial, and insecticidal properties. Endophytes have shown particular promise in agriculture particularly as beneficial crop inoculants and are known to enhance abiotic and biotic plant stress tolerance by increasing tolerance to drought and water stress, as well as tolerance to high temperature and high salinity. A better understanding of their plant growth-promoting mechanisms could simplify higher production of energy crops in a more sustainable manner even on marginal land and feed stocks for industrial processes, thus contribute to avoiding conflicts between food and energy production Many endophytes can be exploited to improve the efficiency of phytoremediation as they are found to be resistant to heavy metals and capable of detoxifying organic contaminants.

scholarly journals Importance of N-Acyl-Homoserine Lactone-Based Quorum Sensing and Quorum Quenching in Pathogen Control and Plant Growth Promotion

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1561
Author(s):  
Anton Hartmann ◽  
Sophia Klink ◽  
Michael Rothballer
Keyword(s):  
Biological Control ◽  
Quorum Sensing ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Growth Promotion ◽  
Quorum Quenching ◽  
Plant Interactions ◽  
Pathogen Control

The biological control of plant pathogens is linked to the composition and activity of the plant microbiome. Plant-associated microbiomes co-evolved with land plants, leading to plant holobionts with plant-beneficial microbes but also with plant pathogens. A diverse range of plant-beneficial microbes assists plants to reach their optimal development and growth under both abiotic and biotic stress conditions. Communication within the plant holobiont plays an important role, and besides plant hormonal interactions, quorum-sensing signalling of plant-associated microbes plays a central role. Quorum-sensing (QS) autoinducers, such as N-acyl-homoserine lactones (AHL) of Gram-negative bacteria, cause a pronounced interkingdom signalling effect on plants, provoking priming processes of pathogen defence and insect pest control. However, plant pathogenic bacteria also use QS signalling to optimise their virulence; these QS activities can be controlled by quorum quenching (QQ) and quorum-sensing inhibition (QSI) approaches by accompanying microbes and also by plants. Plant growth-promoting bacteria (PGPB) have also been shown to demonstrate QQ activity. In addition, some PGPB only harbour genes for AHL receptors, so-called luxR-solo genes, which can contribute to plant growth promotion and biological control. The presence of autoinducer solo receptors may reflect ongoing microevolution processes in microbe–plant interactions. Different aspects of QS systems in bacteria–plant interactions of plant-beneficial and pathogenic bacteria will be discussed, and practical applications of bacteria with AHL-producing or -quenching activity; QS signal molecules stimulating pathogen control and plant growth promotion will also be presented.

Plastic Mulch Color Effects on Light Micro-environment and Watermelon Plant Growth

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 474d-474
Author(s):  
N.K. Damayanthi Ranwala ◽  
Dennis R. Decoteau
Keyword(s):  
Plant Growth ◽  
Light Transmission ◽  
Root Zone ◽  
Dry Mass ◽  
Plant Responses ◽  
Plastic Mulch ◽  
Plant Parts ◽  
Reflected Light ◽  
Total Light ◽  
Dry Mass Partitioning

This study was conducted to evaluate the spectral properties of various colored plastic color mulches and to determine the effects of upwardly reflected light from the mulch surfaces on watermelon plant growth when differences in root zone temperatures are minimized. Two-week-old watermelon plants were grown with black mulch, red-painted mulch, SRM-Red mulch (Sonoco, Inc., Harstville, S.C.), and white mulch. Total light reflection (58 μmol·m–2·s–1 in 400–700 nm) and red: far-red (R:FR = 0.44) of reflected light were lower in black mulch and highest in white mulch (634 and 0.92, respectively). Both black mulch and white mulch had same blue:red (B:R = 0.6) while white mulch had higher B:FR (0.58) in reflected light compared to black mulch (0.26). Reflective properties of red mulches were somewhat similar, and R:FR, B:R, and B:FR were 0.8, 0.2, and 0.18, respectively. However, SRM-Red mulch had highest total light (355 μmol·m–2·s–1 in 400–700 nm) transmission through the mulch, and R:FR, B:R, and B:FR were 0.84, 0.28, and 0.23, respectively. Light transmission through the other mulches was nonsignificant. Watermelon plants grown with black mulch and red mulches had higher internode lengths compared to white mulch after 20 days. Further, plants grown under black had significant higher petiole elongation accompanied with higher dry mass partitioning to petioles, and lower partitioning to roots, stems, and leaves. There was no effects of surface mulch color on total plant dry mass or photosynthesis although plants with black had higher transpiration rate. This suggests the differential regulation of dry mass partitioning among plant parts due to mulch color. The similar plant responses with black mulch and white mulch to plants treated with FR or R light at the end of photoperiod implies the involvement of phytochrome regulation of growth due to mulch surface color.

scholarly journals DASH-type cryptochromes – solved and open questions

2020 ◽  
Vol 401 (12) ◽  
pp. 1487-1493
Author(s):  
Stephan Kiontke ◽  
Tanja Göbel ◽  
Annika Brych ◽  
Alfred Batschauer
Keyword(s):  
Dna Repair ◽  
Circadian Clock ◽  
Blue Light ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Open Questions ◽  
Essential Components ◽  
Repair Activity ◽  
Almost All ◽  
Uv Lesions

AbstractDrosophila, Arabidopsis, Synechocystis, human (DASH)-type cryptochromes (cry-DASHs) form one subclade of the cryptochrome/photolyase family (CPF). CPF members are flavoproteins that act as DNA-repair enzymes (DNA-photolyases), or as ultraviolet(UV)-A/blue light photoreceptors (cryptochromes). In mammals, cryptochromes are essential components of the circadian clock feed-back loop. Cry-DASHs are present in almost all major taxa and were initially considered as photoreceptors. Later studies demonstrated DNA-repair activity that was, however, restricted to UV-lesions in single-stranded DNA. Very recent studies, particularly on microbial organisms, substantiated photoreceptor functions of cry-DASHs suggesting that they could be transitions between photolyases and cryptochromes.

scholarly journals Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 164-176
Author(s):  
Abdallah S. Abdelsattar ◽  
Anan Safwat ◽  
Rana Nofal ◽  
Amera Elsayed ◽  
Salsabil Makky ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Wide Range ◽  
Almost All ◽  
And Control ◽  
Milk And Dairy Products

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

scholarly journals Hormesis with glyphosate depends on coffee growth stage

2013 ◽  
Vol 85 (2) ◽  
pp. 813-822 ◽  
Author(s):  
LEONARDO B. DE CARVALHO ◽  
PEDRO L.C.A. ALVES ◽  
STEPHEN O. DUKE
Keyword(s):  
Plant Growth ◽  
Weed Management ◽  
Growth Stage ◽  
Growth Stages ◽  
Coffee Plant ◽  
Herbicide Application ◽  
Coffee Plantations ◽  
Plant Growth Stages ◽  
Coffee Plants ◽  
Almost All

Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on coffee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.

scholarly journals Performance of twelve mango cultivars grown in different agroecological zones of Bangladesh

2013 ◽  
Vol 37 (4) ◽  
pp. 691-710 ◽  
Author(s):  
K Kobra ◽  
MA Hossain ◽  
MAH Talukder ◽  
MAJ Bhuyan
Keyword(s):  
Plant Growth ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Soluble Solids Content ◽  
Flower Production ◽  
Pests And Diseases ◽  
Agroecological Zones ◽  
Solids Content ◽  
Almost All ◽  
Perfect Flower

Twelve commercial and promising mango cultivars were evaluated at three agroecological zones of Bangladesh viz., Akbarpur (AEZ 29), Chapai Nawabgonj (AEZ 11), and Gazipur (AEZ 28) during 2006-07 to investigate their regional adaptability. Cultivars included in the experiment were Ashwina, BARI Aam-1, Bombai, Deori, Fazli, Gopalbhog, Kalia, Khirsapat, Langra, Lata Bombai, Rani Passand, and Surjapuri. The plants were transplanted in the field during July 1993. Tree volume was the maximum (79.78 m3) in Khirsapat and the minimum in Lata Bombai (21.92 m3). Langra had the highest percentage of perfect flower (27%), while the lowest was in Deori and Kalia (5%). The earliest and latest fruit was harvested from BARI Aam-1 and Ashwina, respectively, at all locations. All the cultivars were harvested 3-5 and 8-10 days earlier at Akbarpur and Gazipur, respectively, compared to that at Chapai Nawabgonj. The highest individual fruit weight was obtained from Fazli at all locations, while Gopalbhog (130 g) had the lowest fruit weight at Akbarpur and Surjapuri at Chapai Nawabgonj (172 g) and Gazipur (140 g). Total soluble solids content was reasonably high in all the cultivars at each location (around 20%) except Ashwina, Lata Bombai, and Surjapuri which contained around 16% TSS. Lata Bombai was highly susceptible to anthracnose, floral malformation, and stem-end-rot at almost all the locations. Other cultivars showed low to medium susceptibility to all these diseases. The highest and lowest fruit producing cultivars were Khirsapat (206) and Lata Bombai (106) at Gazipur, while Rani Passand (196) and Bombai, Lata Bombai (92) at Akbarpur but at Chapai Nawabgonj, these were Langra (325) and Deori (117), respectively. Cultivar Fazli (83.61 kg) was the highest yielder by weight, while Lata Bombai (18.35 kg) was the lowest. Among the locations, Chapai Nawabgonj was the most favourable for plant growth, perfect flower production, and yield, and least favourable for pests and diseases. The overall result of the experiment indicated that good quality mango could also be grown successfully under Akbarpur and Gazipur conditions adopting appropriate variety like Khirsapat. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14394 Bangladesh J. Agril. Res. 37(4): 691-710, December 2012

scholarly journals A semi-dominant mutation in OsCESA9 improves biomass enzymatic digestibility and salt tolerance by relatively remodeling cell walls in rice

2020 ◽  
Author(s):  
Yafeng Ye ◽  
Shuoxun Wang ◽  
Kun Wu ◽  
Yan Ren ◽  
Hongrui Jiang ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Rice Straw ◽  
Enzymatic Saccharification ◽  
Cellulose Content ◽  
Normal Plant ◽  
Wild Type ◽  
Negative Effects ◽  
Straw Return ◽  
Almost All

Abstract Background: Cellulose synthase (CESA) mutants have potential use in straw processing due to their lower cellulose content, but almost all of the mutants exhibit defective phenotypes in plant growth and development. Balancing normal plant growth with reduced cellulose content remains a challenge, as cellulose content and normal plant growth are typically negatively correlated with one another. Result: Here, the rice (Oryza sativa) semi-dominant brittle culm (sdbc) mutant Sdbc1, which harbors a substitution (D387N) at the first conserved aspartic acid residue of OsCESA9, exhibits lower cellulose content and reduced secondary wall thickness as well as enhanced biomass enzymatic saccharification compared with the wild type (WT). Further experiments indicated that the OsCESA9D387N mutation may compete with the wild-type OsCESA9 for interacting with OsCESA4 and OsCESA7, further forming non-functional or partially functional CSCs. The OsCESA9/OsCESA9D387N heterozygous plants increase salt tolerance through scavenging and detoxification of ROS and indirectly affecting related gene expression. They also improve rice straw return to the field due to their brittle culms and lower cellulose content without any negative effects in grain yield and lodging. Conclusion: Hence, manipulation of OsCESA9D387N can provide the perspective of the rice straw for biofuels and bioproducts due to its improved enzymatic saccharification.

scholarly journals Arbuscular Mycorrhizal Fungal Diversity In Medicinal Plants Of Sirumalai Hills, Eastern Ghats And Their Role In Melia Dubia Cav

2021 ◽  
Author(s):  
Santhoshkumar S ◽  
Nagarajan N
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Eastern Ghats ◽  
Nutrient Cycle ◽  
Plant Responses ◽  
Plant Interactions ◽  
Plant Tolerance ◽  
Agricultural Ecosystem ◽  
Microbial World ◽  
Melia Dubia ◽  
Arbuscular Mycorrhizal Fungal

The microbial World is the largest unexplored reservoir of biodiversity on earth. Interest in the exploration of microbial diversity has been promoted by the fact that a microbe performs numerous functions essential for the biosphere that include nutrient cycle and environmental detoxification. Notably, under natural circumstances, plants frequently interact with microbes,which directly arbitrate plant responses to environmental adversities. Some microbe-plant interactions lead to a mitigation of stress-related damages and improvement of plant tolerance to stressful conditions. As a crucial element of soils, microbes are an integral part of the agricultural ecosystem.

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