The Role of Endogenous Strigolactones and Their Interaction with ABA during the Infection Process of the Parasitic Weed Phelipanche ramosa in Tomato Plants

The root-parasitic weed Phelipanche ramosa (L.) Pomel represents a major problem for processing tomato crops. The control of this holoparasitic plant is difficult, and better understanding of treatment methods is needed to develop new and specific control strategies. This study investigated 12 agronomic, chemical, biological and biotechnological strategies for the control of this parasitic weed, in comparison with the untreated situation. The trial was carried out in 2014 at the Department of Agriculture, Food and the Environment of the University of Foggia (southern Italy), using processing tomato plants grown in pots filled with soil from a field that was heavily infested with P. ramosa. After transplantation, top dressing was performed with 70 kg ha–1 nitrogen. A randomised block design with 3 replicates (pots) was adopted. During the growing cycle of the tomato, at 70, 75, 81 and 88 days after transplantation, the number of parasitic shoots (branched plants) that had emerged in each pot was determined, and the leaf chlorophyll of the plants was measured using a soil-plantanalysis- development meter. At harvesting on 8 August 2014, the major quanti-qualitative yield parameters were determined, including marketable yield, mean weight, dry matter, soluble solids, and fruit colour. The results show lower chlorophyll levels in the parasitised tomato plants, compared to healthy plants. None of the treatments provided complete control against P. ramosa. However, among the methods tested, Radicon® biostimulant (Radicon, Inc., Elk Grove Village, IL, USA), compost activated with Fusarium oxysporum, nitrogen and sulphur mineral fertilisers, EnzoneTM soil fumigant (Elliott Chemicals Ltd., Auckland, New Zealand), and a resistant tomato genotype mitigated the virulence of the attacks of this parasite. These effects should be improved by combining some of these treatments, especially for gradual and continued reduction in the seed bank of the parasite in the soil. For the tomato yields across the different treatments, there were no significant differences seen; however, the yields showed an improving trend for treatments with lower presence of the P. ramosa weed.

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Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

Journal of Bacteriology ◽

10.1128/jb.183.12.3597-3605.2001 ◽

2001 ◽

Vol 183 (12) ◽

pp. 3597-3605 ◽

Cited By ~ 201

Author(s):

Julie Tans-Kersten ◽

Huayu Huang ◽

Caitilyn Allen

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Soft Agar ◽

Cell Protein ◽

In Planta ◽

Tomato Plants ◽

Bacterial Wilt Disease ◽

Virulence Assay ◽

Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

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Agronomic, breeding, and biotechnological approaches to parasitic plant management through manipulation of germination stimulant levels in agricultural soils

Botany ◽

10.1139/b11-075 ◽

2011 ◽

Vol 89 (12) ◽

pp. 813-826 ◽

Cited By ~ 29

Author(s):

M. Fernández-Aparicio ◽

J.H. Westwood ◽

D. Rubiales

Keyword(s):

Mycorrhizal Fungi ◽

Agricultural Soils ◽

Host Recognition ◽

Plant Management ◽

Parasitic Weed ◽

Germination Stimulant ◽

New Class ◽

Agronomic Practices ◽

Number Of Plant Species

A number of plant species have adapted to parasitize other plants, and some parasitic species pose severe constraints to major crops. The role of strigolactones and other metabolites present in host root exudates as germination stimulants for weedy root parasitic weed seeds has been known for the last 40 years. Recently, the ecological and developmental roles of strigolactones have been clarified by the discovery that they are a new class of plant hormone that controls shoot branching and serve as host recognition signals for mycorrhizal fungi. Parasitic plants also recognize these chemicals and use them to coordinate their life cycle with that of their host. Here we review agronomic practices that use parasitic germination stimulant production as a target for manipulation to control parasitic weeds.

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Role of ethylene and light in chitosan-induced local and systemic defence responses of tomato plants

Journal of Plant Physiology ◽

10.1016/j.jplph.2021.153461 ◽

2021 ◽

pp. 153461

Author(s):

Zalán Czékus ◽

Nadeem Iqbal ◽

Boglárka Pollák ◽

Atina Martics ◽

Attila Ördög ◽

...

Keyword(s):

Tomato Plants ◽

Defence Responses

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ROLE OF ROOTSTOCKS ON ION UPTAKE OF TOMATO PLANTS GROWN UNDER SALINE CONDITIONS

Acta Horticulturae ◽

10.17660/actahortic.2009.807.95 ◽

2009 ◽

pp. 637-642 ◽

Cited By ~ 3

Author(s):

G.B. Öztekin ◽

C. Leonardi ◽

E. Caturano ◽

M. Martorana ◽

Y. Tüzel

Keyword(s):

Ion Uptake ◽

Tomato Plants

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The role of strigolactones in host specificity ofOrobancheandPhelipancheseed germination

Seed Science Research ◽

10.1017/s0960258510000371 ◽

2010 ◽

Vol 21 (1) ◽

pp. 55-61 ◽

Cited By ~ 58

Author(s):

Mónica Fernández-Aparicio ◽

Koichi Yoneyama ◽

Diego Rubiales

Keyword(s):

Seed Germination ◽

Host Specificity ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Parasitic Plants ◽

Parasitic Weed ◽

Low Concentrations ◽

Weedy Species ◽

Germination Requirements

AbstractStrigolactones are apocarotenoids regulating shoot branching. They are also known to be exuded by plant roots at very low concentrations, stimulating hyphal branching of arbuscular mycorrhizal fungi and germination of root parasitic weed seeds. We show that strigolactones play a major role in host specificity ofOrobancheandPhelipanche(the broomrapes) seed germination. This observation confirms that host-derived germination stimulants are an important component determining the host specificity of these parasitic plants. Weedy broomrape species were less specialized in germination requirements than the non-weedy species except forO. cumanaandO. foetidavar.broteri. Similar results were obtained with the root exudates. Some species, such asP. aegyptiacaandO. minor, showed a broad spectrum of host specificity in terms of seed germination, which was stimulated by exudates from the majority of species tested, whereas others, such asO. cumana,O. hederaeandO. densiflora, were highly specific. Some species, such asO. minor,P. aegyptiacaandP. nana, were responsive to the three strigolactones studied, whereas others were induced by only one of them, or did not respond to them at all. The synthetic strigolactone analogue GR24, generally used as a standard for germination tests, was not effective on someOrobancheandPhelipanchespecies. Seeds of some species that did not respond to GR24 were induced to germinate in the presence of fabacyl acetate or strigol, confirming the role of strigolactones in host specificity.

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Comparative analysis reveals gravity is involved in the MIZ1-regulated root hydrotropism

Journal of Experimental Botany ◽

10.1093/jxb/eraa409 ◽

2020 ◽

Vol 71 (22) ◽

pp. 7316-7330

Author(s):

Ying Li ◽

Wei Yuan ◽

Luocheng Li ◽

Hui Dai ◽

Xiaolin Dang ◽

...

Keyword(s):

Water Potential ◽

Double Mutant ◽

Root Elongation ◽

Vertical Orientation ◽

Tomato Plants ◽

Oblique Orientation ◽

Experimental Systems ◽

Potential Gradients ◽

Insight Into

Abstract Hydrotropism is the directed growth of roots toward the water found in the soil. However, mechanisms governing interactions between hydrotropism and gravitropism remain largely unclear. In this study, we found that an air system and an agar–sorbitol system induced only oblique water-potential gradients; an agar–glycerol system induced only vertical water-potential gradients; and a sand system established both oblique and vertical water-potential gradients. We employed obliquely oriented and vertically oriented experimental systems to study hydrotropism in Arabidopsis and tomato plants. Comparative analyses using different hydrotropic systems showed that gravity hindered the ability of roots to search for obliquely oriented water, whilst facilitating roots’ search for vertically oriented water. We found that the gravitropism-deficient mutant aux1 showed enhanced hydrotropism in the oblique orientation but impaired root elongation towards water in the vertical orientation. The miz1 mutant exhibited deficient hydrotropism in the oblique orientation but normal root elongation towards water in the vertical orientation. Importantly, in contrast to miz1, the miz1/aux1 double mutant exhibited hydrotropic bending in the oblique orientation and attenuated root elongation towards water in the vertical orientation. Our results suggest that gravitropism is required for MIZ1-regulated root hydrotropism in both the oblique orientation and the vertical orientation, providing further insight into the role of gravity in root hydrotropism.

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Expression of miR159 Is Altered in Tomato Plants Undergoing Drought Stress

Plants ◽

10.3390/plants8070201 ◽

2019 ◽

Vol 8 (7) ◽

pp. 201 ◽

Cited By ~ 3

Author(s):

María José López-Galiano ◽

Inmaculada García-Robles ◽

Ana I. González-Hernández ◽

Gemma Camañes ◽

Begonya Vicedo ◽

...

Keyword(s):

Transcription Factor ◽

Drought Stress ◽

Regulatory Networks ◽

Crop Yields ◽

Insect Pest ◽

Regulatory Function ◽

Myb Transcription Factor ◽

Regulation Of Transcription ◽

Tomato Plants

In a scenario of global climate change, water scarcity is a major threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in many plant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and its target SlMYB transcription factor genes in tomato plants of cv. Ailsa Craig grown in deprived water conditions or in response to mechanical damage caused by the Colorado potato beetle, a devastating insect pest of Solanaceae plants. Results showed that sly-miR159 regulatory function in the tomato plants response to distinct stresses might be mediated by differential stress-specific MYB transcription factor targeting. sly-miR159 targeting of SlMYB33 transcription factor transcript correlated with accumulation of the osmoprotective compounds proline and putrescine, which promote drought tolerance. This highlights the potential role of sly-miR159 in tomato plants’ adaptation to water deficit conditions.

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miR168 targets Argonaute1A mediated miRNAs regulation pathways in response to potassium deficiency stress in tomato

BMC Plant Biology ◽

10.1186/s12870-020-02660-5 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Xin Liu ◽

Chunchang Tan ◽

Xin Cheng ◽

Xiaoming Zhao ◽

Tianlai Li ◽

...

Keyword(s):

Root Growth ◽

Transgenic Tomato ◽

Integrated Analysis ◽

Regulation Mechanism ◽

Sequencing Analysis ◽

Growth Modulation ◽

Tomato Plants ◽

Transgenic Tomato Plants ◽

Low K

Abstract Background Potassium (K+) is an essential ion for most plants, as it is involved in the regulation of growth and development. K+ homeostasis in plant cells has evolved to facilitate plant adaptation to K+-deficiency stress. Argonaute1 (AGO1) is regulated by miR168 to modulate the small RNA regulatory pathway by RNA silencing complex (RISC) in tomatoes. However, the role of miR168-mediated regulation of AGO1 in the context of K+ deficiency stress in tomatoes has not been elucidated yet. Results SlmiR168 and its target gene SlAGO1A were differentially expressed among low-K+-tolerant JZ34 and low-K+-sensitive JZ18 tomato plants. Transgenic tomato plants constitutively expressing pri-SlmiR168a showed stronger root system growth, better leaves development, and higher K+ contents in roots under K+-deficiency stress than those of the transgenic tomato lines expressing rSlAGO1A (SlmiR168-resistant) and the wild type (WT). Deep sequencing analysis showed that 62 known microRNAs (miRNAs) were up-regulated in 35S:rSlAGO1 compared with WT tomatoes. The same miRNAs were down-regulated in 35S:SlmiR168a compared with WT plants. The integrated analysis found 12 miRNA/mRNA pairs from the 62 miRNAs, including the root growth and cytokinin (CTK)/abscisic acid (ABA) pathways. Conclusions The regulation mediated by SlmiR168 of SlAGO1A contributes to the plant development under low-K+ stress. Moreover, this regulation mechanism may influence downstream miRNA pathways in response to low-K+ stress through the CTK/ABA and root growth modulation pathways.

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Expression of small GTPases in the roots and nodules of Medicago truncatula cv. Jemalong

Acta Botanica Croatica ◽

10.2478/botcro-2019-0008 ◽

2019 ◽

Vol 78 (1) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Abdul Razaque Memon ◽

Christiane Katja Schwager ◽

Karsten Niehaus

Keyword(s):

Medicago Truncatula ◽

Binding Proteins ◽

Polymerase Chain Reaction Analysis ◽

Small Gtpases ◽

Infection Process ◽

Nodule Development ◽

Gtp Binding Proteins ◽

Gtp Binding ◽

Differential Expression Pattern

Abstract In this study we used Medicago truncatula, to identify and analyze the expression of small GTP-binding proteins (Arf1, Arl1, Sar1, Rabs, Rop/Rac) and their interacting partners in the infection process in the roots and nodules. A real-time polymerase chain reaction analysis was carried out and our results showed that Arf1 (AtArfB1c-like), MtSar1, AtRabA1e-like, AtRabC1-like, MsRab11-like and AtRop7-like genes were highly expressed in the nodules of rhizobium inoculated plants compared to the non-inoculated ones. On the contrary, AtRabA3 like, AtRab5c and MsRac1-like genes were highly expressed in non-infected nitrogen supplied roots of M. truncatula. Other Rab genes (AtRabA4a, AtRabA4c and AtRabG3a-like genes) were nearly equally expressed in both treatments. Interestingly, RbohB (a respiratory burst NADPH oxidase homologue) was more highly expressed in rhizobium infected than in non-infected roots and nodules. Our data show a differential expression pattern of small GTP-binding proteins in roots and nodules of the plants. This study demonstrates an important role of small GTP-binding proteins in symbiosome biogenesis and root nodule development in legumes.

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