Natural Biostimulant Attenuates Salinity Stress Effects in Chili Pepper by Remodeling Antioxidant, Ion, and Phytohormone Balances, and Augments Gene Expression

A biostimulant is any microorganism or substance used to enhance the efficiency of nutrition, tolerance to abiotic stress and/or quality traits of crops, depending on its contents from nutrients. Plant biostimulants like honey bee (HB) and silymarin (Sm) are a strategic trend for managing stressed crops by promoting nutritional and hormonal balance, regulating osmotic protectors, antioxidants, and genetic potential, reflecting plant growth and productivity. We applied diluted honey bee (HB) and silymarin-enriched honey bee (HB- Sm) as foliar nourishment to investigate their improving influences on growth, yield, nutritional and hormonal balance, various osmoprotectant levels, different components of antioxidant system, and genetic potential of chili pepper plants grown under NaCl-salinity stress (10 dS m‒1). HB significantly promoted the examined attributes and HB-Sm conferred optimal values, including growth, productivity, K+/Na+ ratio, capsaicin, and Sm contents. The antioxidative defense components were significantly better than those obtained with HB alone. Conversely, levels of oxidative stress markers (superoxide ions and hydrogen peroxide) and parameters related to membrane damage (malondialdehyde level, stability index, ionic leakage, Na+, and Cl− contents) were significantly reduced. HB-Sm significantly affects inactive gene expression, as a natural biostimulator silencing active gene expression. SCoT primers were used as proof in salt-treated or untreated chili pepper plants. There were 41 cDNA amplicons selected by SCoT-primers. Twenty of them were EcDNA amplicons (cDNA-amplicons that enhanced their genes by one or more treatments) representing 49% of all cDNA amplicons, whereas 7 amplicons for ScDNA (whose genes were silenced in one or more treatments) represented 17%, and 14 McDNA (monomorphic cDNA-amplicons with control) amplicons were represented by 34% from all cDNA amplicons. This indicates the high effect of BH-Sm treatments in expression enhancement of some inactive genes and their silenced effect for expression of some active genes, also confirming that cDNA-SCoT markers succeeded in detection of variable gene expression patterns between the untreated and treated plants. In conclusion, HB-Sm as a natural multi-biostimulator can attenuate salt stress effects in chili pepper plants by remodeling the antioxidant defense system and ameliorating plant productivity.

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Differential Response to Water Deficit in Chili Pepper (Capsicum annuum L.) Growing in Two Types of Soil Under Different Irrigation Regimes

Agriculture ◽

10.3390/agriculture10090381 ◽

2020 ◽

Vol 10 (9) ◽

pp. 381

Author(s):

Israel Macias-Bobadilla ◽

Marcela Vargas-Hernandez ◽

Ramon G. Guevara-Gonzalez ◽

Enrique Rico-Garcia ◽

Rosalia V. Ocampo-Velazquez ◽

...

Keyword(s):

Gene Expression ◽

Secondary Metabolism ◽

Water Deficit ◽

Crop Production ◽

Differential Response ◽

Chili Pepper ◽

Water Deficits ◽

Irrigation Regimes ◽

Pharmaceutical Industries ◽

Pepper Plants

Chili pepper (Capsicum spp.) is one of the most economically important horticultural crops in the world; its production for the food and pharmaceutical industries has been increasing worldwide. The economic importance of this crop is due, in part, to the nutraceutical properties derived from its secondary metabolism. Drought is the main environmental factor that affects crop production. Nevertheless, studies involving water deficit have considered short-term responses to sharp water deficit rather than long-term acclimation processes through moderate and gradually increasing water deficits, which omitted the dynamics and profile of the secondary metabolism that are part of the plant’s defence system against this stress factor. The present study aimed to identify the different mechanisms that chili pepper plants use to cope with drought stress using a progressive decrease and increase of water availability, conditions that commonly occur for crops in open fields. Four treatments were applied as follows: gradual water deficit (GWD), initial waterlogging with gradual water deficit (IWGD), sudden water deficit with gradual recovery (SWDR), and no deficit of water (NDW). These conditions should represent a more real situation similar to that faced by plants in the agricultural environment. In order to evaluate the response mechanisms associated with these water deficits, changes in phenological variables, proline accumulation, and the gene expression of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), peroxidase (POD), and superoxide dismutase (SOD) were measured in chili pepper plants growing on land under different irrigation regimes in two contrasting soil types in areas where chili pepper plants are cultivated in central Mexico. The variables evaluated showed a differentiated response of the mechanisms in plants growing under different levels of water deficit. Given the differential response observed for the gene expression and morphological and biochemical variables studied in chili pepper plants against different water regimes, in this work, this may have implications for more efficient use of water in crops with high nutraceutical content, in addition to prospects for using products derived from secondary metabolism in the pharmaceutical industry.

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The Use of Red Shade Nets Improves Growth in Salinized Pepper (Capsicum annuum L.) Plants by Regulating Their Ion Homeostasis and Hormone Balance

Agronomy ◽

10.3390/agronomy10111766 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1766

Author(s):

Amparo Gálvez ◽

Alfonso Albacete ◽

Francisco M. del Amor ◽

Josefa López-Marín

Keyword(s):

Capsicum Annuum ◽

Salinity Stress ◽

Management Strategy ◽

Shoot Growth ◽

Ion Homeostasis ◽

Capsicum Annuum L ◽

Efficient Management ◽

Hormonal Balance ◽

Microclimate Conditions ◽

Pepper Plants

The actual climate crisis scenario is aggravating the abiotic stress episodes that crop plants have to face. Salinity is one of the most important abiotic stresses directly impairing plant growth and productivity. Several strategies have been developed to minimize the negative effects of salinity in agricultural industry, mainly at the plant level, while management strategies, such us the control of microclimate conditions and light quality over plant canopy, have also been used. Indeed, shading plants with photoselective nets has been considered an efficient management strategy to modulate solar radiation to improve crop productivity. The aim of this work was to gain insights about the physiological factors underlying the salinity-alleviating effect of using red shading nets. For that, pepper plants (Capsicum annuum L.) were grown under control (0 mM NaCl) and moderate salinity (35 mM NaCl) conditions, with half of the plants covered with a red net (30% shading). The shoot growth impairment provoked by salinity was in part minimized by shading plants with red nets, which can be explained by their higher capacity to exclude Na+, control of K+ homeostasis and regulation of hormonal balance. Indeed, the concentrations of the most active cytokinin in pepper, trans-zeatin, as well as its metabolic precursor, zeatin riboside, increased in shaded plants, associated to shoot growth recovery and photosynthetic rate maintenance under salinity. Furthermore, the stress-related hormone abscisic acid (ABA) increased with salinity but in a lower extend in the plants shaded with red nets, suggesting a fine tune of stomata opening by ABA which, in crosstalk with salicylic acid increment, improved plant water relations. Likewise, the concentrations of gibberellins and the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, also changed during salinity stress in shaded plants but those changes were uncoupled of growth responses as indicated by the principal component analysis and thus they seem to play a minor role. Our data demonstrate that shading pepper plants with red nets is an efficient management strategy to modulate microclimate conditions at crop level thus controlling the ion homeostasis and hormonal balance of the plant to cope with salinity stress. This is especially important due to the actual and expected changes of the global climatic conditions.

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Neuroanatomical Dissection of the Honey Bee Brain Based on Temporal and Regional Gene Expression Patterns

Honeybee Neurobiology and Behavior ◽

10.1007/978-94-007-2099-2_26 ◽

2011 ◽

pp. 341-357 ◽

Cited By ~ 4

Author(s):

Takeo Kubo

Keyword(s):

Gene Expression ◽

Honey Bee ◽

Expression Patterns ◽

Gene Expression Patterns ◽

Regional Gene

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Gene expression patterns associated with queen honey bee longevity

Mechanisms of Ageing and Development ◽

10.1016/j.mad.2005.07.004 ◽

2005 ◽

Vol 126 (11) ◽

pp. 1230-1238 ◽

Cited By ~ 116

Author(s):

Miguel Corona ◽

Kimberly A. Hughes ◽

Daniel B. Weaver ◽

Gene E. Robinson

Keyword(s):

Gene Expression ◽

Honey Bee ◽

Expression Patterns ◽

Gene Expression Patterns

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Understanding salt tolerance mechanism using transcriptome profiling and de novo assembly of wild tomato Solanum chilense

Scientific Reports ◽

10.1038/s41598-020-72474-w ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

S. P. Kashyap ◽

H. C. Prasanna ◽

Nishi Kumari ◽

Pallavi Mishra ◽

B. Singh

Keyword(s):

Gene Expression ◽

Salt Tolerance ◽

Signaling Pathways ◽

Salinity Stress ◽

Salinity Tolerance ◽

De Novo ◽

Expression Patterns ◽

Differentially Expressed ◽

Ros Scavenging ◽

Solanum Chilense

Abstract Soil salinity affects the plant growth and productivity detrimentally, but Solanum chilense, a wild relative of cultivated tomato (Solanum lycopersicum L.), is known to have exceptional salt tolerance. It has precise adaptations against direct exposure to salt stress conditions. Hence, a better understanding of the mechanism to salinity stress tolerance by S. chilense can be accomplished by comprehensive gene expression studies. In this study 1-month-old seedlings of S. chilense and S. lycopersicum were subjected to salinity stress through application of sodium chloride (NaCl) solution. Through RNA-sequencing here we have studied the differences in the gene expression patterns. A total of 386 million clean reads were obtained through RNAseq analysis using the Illumina HiSeq 2000 platform. Clean reads were further assembled de novo into a transcriptome dataset comprising of 514,747 unigenes with N50 length of 578 bp and were further aligned to the public databases. Genebank non-redundant (Nr), Viridiplantae, Gene Ontology (GO), KOG, and KEGG databases classification suggested enrichment of these unigenes in 30 GO categories, 26 KOG, and 127 pathways, respectively. Out of 265,158 genes that were differentially expressed in response to salt treatment, 134,566 and 130,592 genes were significantly up and down-regulated, respectively. Upon placing all the differentially expressed genes (DEG) in known signaling pathways, it was evident that most of the DEGs involved in cytokinin, ethylene, auxin, abscisic acid, gibberellin, and Ca2+ mediated signaling pathways were up-regulated. Furthermore, GO enrichment analysis was performed using REVIGO and up-regulation of multiple genes involved in various biological processes in chilense under salinity were identified. Through pathway analysis of DEGs, “Wnt signaling pathway” was identified as a novel pathway for the response to the salinity stress. Moreover, key genes for salinity tolerance, such as genes encoding proline and arginine metabolism, ROS scavenging system, transporters, osmotic regulation, defense and stress response, homeostasis and transcription factors were not only salt-induced but also showed higher expression in S. chilense as compared to S. lycopersicum. Thus indicating that these genes may have an important role in salinity tolerance in S. chilense. Overall, the results of this study improve our understanding on possible molecular mechanisms underlying salt tolerance in plants in general and tomato in particular.

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Bacterial endophytes contribute to abiotic stress adaptation in pepper plants (Capsicum annuumL.)

Canadian Journal of Microbiology ◽

10.1139/w07-082 ◽

2007 ◽

Vol 53 (11) ◽

pp. 1195-1202 ◽

Cited By ~ 147

Author(s):

A. H. Sziderics ◽

F. Rasche ◽

F. Trognitz ◽

A. Sessitsch ◽

E. Wilhelm

Keyword(s):

Gene Expression ◽

Abiotic Stress ◽

Osmotic Stress ◽

Expression Patterns ◽

Sweet Pepper ◽

Free Proline ◽

Bacterial Strains ◽

Inducible Genes ◽

Pepper Plants

Endophytes are nonpathogenic plant-associated bacteria that can play an important role in plant vitality and may confer resistance to abiotic or biotic stress. The effects of 5 endophytic bacterial strains isolated from pepper plants showing 1-aminocyclopropane-1-carboxylate deaminase activity were studied in sweet pepper under in vitro conditions. Four of the strains tested showed production of indole acetic acid. Plant growth, osmotic potential, free proline content, and gene expression were monitored in leaves and roots under control and mild osmotic stress conditions. All indole acetate producers promoted growth in Capsicum annuum L. ‘Ziegenhorn Bello’, from which they were isolated. Osmotic stress caused an increase in the content of free proline in the leaves of both inoculated and noninoculated plants. Inoculated control plants also revealed higher proline levels in comparison with noninoculated control plants. Differential gene expression patterns of CaACCO, CaLTPI, CaSAR82A, and putative P5CR and P5CS genes during moderate stress were observed, depending on the bacterium applied. Inoculation with 2 bacterial strains, EZB4 and EZB8 ( Arthrobacter sp. and Bacillus sp., respectively), resulted in a significantly reduced upregulation or even downregulation of the stress-inducible genes CaACCO and CaLTPI, as compared with the gene expression in noninoculated plants. This indicates that both strains reduced abiotic stress in pepper under the conditions tested.

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