Emerging role of roots in plant responses to aboveground insect herbivory

2013 ◽  
Vol 20 (3) ◽  
pp. 286-296 ◽  
Author(s):  
Vamsi J. Nalam ◽  
Jyoti Shah ◽  
Punya Nachappa
2021 ◽  
Author(s):  
María Sanz‐Fernández ◽  
Alejandro Rodríguez‐González ◽  
Luisa M. Sandalio ◽  
María C. Romero‐Puertas

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiao Wang ◽  
Chenfei Zheng ◽  
Xiangqi Shao ◽  
Zhangjian Hu ◽  
Jianxin Li ◽  
...  

AbstractWith global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.


1991 ◽  
Vol 17 (9) ◽  
pp. 1821-1836 ◽  
Author(s):  
Gary W. Felton ◽  
Sean S. Duffey
Keyword(s):  

2018 ◽  
Vol 19 (11) ◽  
pp. 3590 ◽  
Author(s):  
Greg Clark ◽  
Stanley Roux

Among the most recently discovered chemical regulators of plant growth and development are extracellular nucleotides, especially extracellular ATP (eATP) and extracellular ADP (eADP). Plant cells release ATP into their extracellular matrix under a variety of different circumstances, and this eATP can then function as an agonist that binds to a specific receptor and induces signaling changes, the earliest of which is an increase in the concentration of cytosolic calcium ([Ca2+]cyt). This initial change is then amplified into downstream-signaling changes that include increased levels of reactive oxygen species and nitric oxide, which ultimately lead to major changes in the growth rate, defense responses, and leaf stomatal apertures of plants. This review presents and discusses the evidence that links receptor activation to increased [Ca2+]cyt and, ultimately, to growth and diverse adaptive changes in plant development. It also discusses the evidence that increased [Ca2+]cyt also enhances the activity of apyrase (nucleoside triphosphate diphosphohydrolase) enzymes that function in multiple subcellular locales to hydrolyze ATP and ADP, and thus limit or terminate the effects of these potent regulators.


2005 ◽  
Vol 17 (1) ◽  
pp. 21-34 ◽  
Author(s):  
María P. Benavides ◽  
Susana M. Gallego ◽  
María L. Tomaro

Heavy metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional, and environmental reasons. Plants posses homeostatic cellular mechanisms to regulate the concentration of metal ions inside the cell to minimize the potential damage that could result from the exposure to nonessential metal ions. This paper summarizes present knowledge in the field of higher plant responses to cadmium, an important environmental pollutant. Knowledge concerning metal toxicity, including mechanisms of cadmium homeostasis, uptake, transport and accumulation are evaluated. The role of the cell wall, the plasma membrane and the mycorrhizas, as the main barriers against cadmium entrance to the cell, as well as some aspects related to phytochelatin-based sequestration and compartmentalization processes are also reviewed. Cadmium-induced oxidative stress was also considered as one of the most studied topics of cadmium toxicity.


Author(s):  
José A. Hernández ◽  
Pedro Diaz-Vivancos ◽  
Gregorio Barba-Espín ◽  
María José Clemente-Moreno

2021 ◽  
Author(s):  
Marisol Giustozzi ◽  
Santiago Freytes ◽  
Aime Jaskolowski ◽  
Micaela Lichy ◽  
Julieta L. Mateos ◽  
...  

Mediator 17 (MED17) is a subunit of the Mediator complex that regulates transcription initiation in eukaryotic organisms. In yeast and humans, MED17 also participates in DNA repair, physically interacting with proteins of the Nucleotide Excision DNA Repair system. We here analyzed the role of MED17 in Arabidopsis plants exposed to UV-B radiation, which role has not been previously described. Comparison of med17 mutant transcriptome to that of WT plants showed that almost one third of transcripts with altered expression in med17 plants are also changed by UV-B exposure in WT plants. To validate the role of MED17 in UV-B irradiated plants, plant responses to UV-B were analyzed, including flowering time, DNA damage accumulation and programmed cell death in the meristematic cells of the root tips. Our results show that med17 and OE MED17 plants have altered responses to UV-B; and that MED17 participates in various aspects of the DNA damage response (DDR). Increased sensitivity to DDR after UV-B in med17 plants can be due to altered regulation of UV-B responsive transcripts; but additionally MED17 physically interacts with DNA repair proteins, suggesting a direct role of this Mediator subunit during repair. Finally, we here also show that MED17 is necessary to regulate the DDR activated by ATR, and that PDCD5 overexpression reverts the deficiencies in DDR shown in med17 mutants. Together, the data presented demonstrates that MED17 is an important regulator of the DDR after UV-B radiation in Arabidopsis plants.


2015 ◽  
Vol 34 (4) ◽  
pp. 720-736 ◽  
Author(s):  
Adam Rajsz ◽  
Anna Warzybok ◽  
Magdalena Migocka

AbstractFull-size members of the ABCG (ATP-binding cassette, subfamily G) subfamily of ABC transporters have been found only in plants and fungi. The plant genes encoding full-size ABCGs identified so far appeared to be differentially regulated under various environmental constraints, plant growth regulators, and microbial elicitors, indicating a broad functional role of these proteins in plant responses to abiotic and biotic stress. Nevertheless, the structure and physiological function of full-size ABCGs in many plant species are still unknown. We have recently identified 16 genes encoding full-size ABCG proteins in cucumber and found that the transcripts of two of them, CsABCG36 (CsPDR8) and CsABCG40 (CsPDR12), are most abundant in roots and are significantly affected by phytohormones and auxin herbicide. In this study, we analyzed the structure and phylogeny of all the full-size cucumber ABCG transporters and studied the organ expression profiles of the remaining 14 CsABCG genes. In addition, we investigated the effect of different plant growth regulators and the diterpene sclareolide on CsABCG expression in cucumber roots. Until now, the full-size plant ABCG transporters have been grouped into five different clusters. The new phylogenetic analysis of full-size ABCGs from model plants and cucumber clustered these proteins into six different subgroups. Interestingly, the expression profiles of cucumber ABCG genes assigned to the same clusters were not correlated, suggesting functional diversification or different regulatory mechanisms of the full-size cucumber ABCG proteins.


Author(s):  
Zubair A. Dar ◽  
Bhat Rifat ◽  
Javeed I. A. Bhat ◽  
Asma Absar Bhatti ◽  
Shamsul Haq ◽  
...  

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.


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