scholarly journals Dodder-transmitted mobile signals prime host plants for enhanced salt tolerance

2019 ◽  
Vol 71 (3) ◽  
pp. 1171-1184 ◽  
Author(s):  
Shalan Li ◽  
Jingxiong Zhang ◽  
Hui Liu ◽  
Nian Liu ◽  
Guojing Shen ◽  
...  

Abstract The dodders (Cuscuta spp.) are a genus of shoot parasites. In nature, a dodder often simultaneously parasitizes two or more neighboring hosts. Salt stress is a common abiotic stress for plants. It is unclear whether dodder transmits physiologically relevant salt stress-induced systemic signals among its hosts and whether these systemic signals affect the hosts’ tolerance to salt stress. Here, we simultaneously parasitized two or more cucumber plants with dodder. We found that salt treatment of one host highly primed the connected host, which showed strong decreases in the extent of leaf withering and cell death in response to subsequent salt stress. Transcriptomic analysis indicated that 24 h after salt treatment of one cucumber, the transcriptome of the other dodder-connected cucumber largely resembled that of the salt-treated one, indicating that inter-plant systemic signals primed these dodder-connected cucumbers at least partly through transcriptomic reconfiguration. Furthermore, salt treatment of one of the cucumbers induced physiological changes, including altered proline contents, stomatal conductance, and photosynthetic rates, in both of the dodder-connected cucumbers. This study reveals a role of dodder in mediating salt-induced inter-plant signaling among dodder-connected hosts and highlights the physiological function of these mobile signals in plant–plant interactions under salt stress.

2008 ◽  
Vol 190 (13) ◽  
pp. 4706-4715 ◽  
Author(s):  
Alan Williams ◽  
Adam Wilkinson ◽  
Martin Krehenbrink ◽  
Daniela M. Russo ◽  
Angeles Zorreguieta ◽  
...  

ABSTRACT The Rhizobium leguminosarum biovar viciae genome contains several genes predicted to determine surface polysaccharides. Mutants predicted to affect the initial steps of polysaccharide synthesis were identified and characterized. In addition to the known cellulose (cel) and acidic exopolysaccharide (EPS) (pss) genes, we mutated three other loci; one of these loci (gmsA) determines glucomannan synthesis and one (gelA) determines a gel-forming polysaccharide, but the role of the other locus (an exoY-like gene) was not identified. Mutants were tested for attachment and biofilm formation in vitro and on root hairs; the mutant lacking the EPS was defective for both of these characteristics, but mutation of gelA or the exoY-like gene had no effect on either type of attachment. The cellulose (celA) mutant attached and formed normal biofilms in vitro, but it did not form a biofilm on root hairs, although attachment did occur. The cellulose-dependent biofilm on root hairs appears not to be critical for nodulation, because the celA mutant competed with the wild-type for nodule infection. The glucomannan (gmsA) mutant attached and formed normal biofilms in vitro, but it was defective for attachment and biofilm formation on root hairs. Although this mutant formed nodules on peas, it was very strongly outcompeted by the wild type in mixed inoculations, showing that glucomannan is critical for competitive nodulation. The polysaccharide synthesis genes around gmsA are highly conserved among other rhizobia and agrobacteria but are absent from closely related bacteria (such as Brucella spp.) that are not normally plant associated, suggesting that these genes may play a wide role in bacterium-plant interactions.


2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Pooja Mohinani ◽  
Taruna Mohinani ◽  
Bharat Bhooshan ◽  
Devesh Kumar

Exposure of plants to diversity of abiotic stresses such as salinity stress retard growth and development of plants which results in huge yield loss worldwide. Plants respond to salinity in unique and complex way that involves many biochemical and physiological changes in plant system. Plant hormones are known to play indispensable roles to elicit an adaptive response in plants under salinity stress. A basic understanding of biological knowledge about the damage that salt stress has on plants and the salt stress tolerance mechanisms is necessary to discover future implications to overcome the effect of salt stress on plants. The main aim of present article is to enhance our knowledge of how salt stress may impact the physiological features of plants and to narrate the potential roles of various phytohormones against the salinity stress at both physiological and molecular grounds.


2017 ◽  
Vol 76 (2) ◽  
pp. 154-162 ◽  
Author(s):  
Roomana Yasmeen ◽  
Zamin Shaheed Siddiqui

AbstractThe physiological response of crop plants againstTrichoderma harzianum(Th-6) in a saline habitat was studied.Trichoderma harzianum(Th-6) is an endophytic fungus that shows salt tolerance and establishes a symbiotic relationship with a host plant. To evaluate the role ofTrichoderma harzianum(Th-6) in mitigating the consequences of salinity stress on crop plants, seeds of maize and rice were coated withTrichodermabefore sowing and salt treatment. Later, after germination, twenty-one day old seedlings were subjected to NaCl concentrations (50, 100 and 150 mM). Salinity negatively affected all investigated physiological parameters in both crops. Treatment of seeds withTrichodermaimproved plant growth andTh-treated plants exhibited substantial physiological adjustment in a saline environment compared toTh-untreated plants. TheTh-treated plants under salt stress showed higher relative water content and stomatal conductance, better photosynthetic performance and higher pigment concentrations, as well as higher catalase and superoxide dismutase activities. Moreover, proline content in salt stress environment was higher inTh-treated plants, while H2O2content declined. The physiological role ofTrichoderma harzianumin mitigating the salt related consequences of both crop plants is discussed.


2016 ◽  
Vol 74 (1) ◽  
pp. 57-72
Author(s):  
Donia Bouthour ◽  
Tawba Kalai ◽  
Houda Gouia ◽  
Chaffei-Haouari Chiraz

Abstract Salt stress is a major abiotic stress that limits agricultural productivity in many regions of the world. To understand the molecular basis of the salt stress response, two wheat (Triticum durum Desf.) cultivars, Karim and Azizi, which are of agronomic significance in Tunisia, were grown under non-saline and saline conditions (100 mM). Leaves and roots of control and salt-stressed plants were harvested after 11 days of salt treatment. Karim cultivar may behave as a typical Na+ include, which compartmentalizes Na+ within the leaf cell vacuoles where it could be used as an osmoticum to lower the osmotic potential necessary for the maintenance of the plant hydric status. While, accumulation of K+ was greater in Karim cultivar compared to Azizi, in both organs, presenting an important manifestation of salinity tolerance. Significant changes in metabolism of antioxidative system were observed, with an increase in protein tyrosine nitration, which indicates that salinity stress induces a nitro-oxidative stress.


2017 ◽  
Vol 61 (4) ◽  
pp. 33-42 ◽  
Author(s):  
Sławomir Kujawski ◽  
Joanna Słomko ◽  
Monika Zawadka-Kunikowska ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
...  

Abstract Introduction Among experienced divers, dive adaptation is seen as a modified pattern of physiological changes. This is reflected, inter alia, in the change in cardiovascular responses, therefore there is need to examine the role of the autonomic nervous system in cardiovascular response modulation after hyperbaric exposure. Material and methods Ten experienced divers took part in the study. The effects of hyperbaric exposure at 30 and 60 meters and interaction (depth x time) were measured. Changes in HR, RRI, CI and HRV values have been taken into analysis. Results Hyperbaric exposure at 30 meters significantly affected HFnu-RRI elevation and decrease of LFnu-RRI (F = 42.92, p <0.00001), without significant affecting the HR, RRI and CI. Exposure to hyperbaric 60 m increased HR and CI (F = 7.64, p = 0.01 and F = 4.89, p = 0.04 respectively) and RRI (F = 7.69, p = 0.01), without significant impact on other variables. The influence of interaction (depth x time) was significant in all measured variables. Conclusions The results indicate that hyperbaric exposure at 60 meters affected HR, RRI, CI parameters, that were not significantly affected by hyperbaric exposure at 30 meters. On the other hand, the exposure at 30 meters showed a significant effect on the LFnu and HFnu HRV, which were not significantly affected by the exposure at 60 meters. Significant effect of time and depth interaction in each of the analyzed variables was observed.


1995 ◽  
Vol 74 (05) ◽  
pp. 1271-1275 ◽  
Author(s):  
C M A Henkens ◽  
V J J Bom ◽  
W van der Schaaf ◽  
P M Pelsma ◽  
C Th Smit Sibinga ◽  
...  

SummaryWe measured total and free protein S (PS), protein C (PC) and factor X (FX) in 393 healthy blood donors to assess differences in relation to sex, hormonal state and age. All measured proteins were lower in women as compared to men, as were levels in premenopausal women as compared to postmenopausal women. Multiple regression analysis showed that both age and subgroup (men, pre- and postmenopausal women) were of significance for the levels of total and free PS and PC, the subgroup effect being caused by the differences between the premenopausal women and the other groups. This indicates a role of sex-hormones, most likely estrogens, in the regulation of levels of pro- and anticoagulant factors under physiologic conditions. These differences should be taken into account in daily clinical practice and may necessitate different normal ranges for men, pre- and postmenopausal women.


1998 ◽  
pp. 61-62
Author(s):  
N. S. Jurtueva

In the XIV century. centripetal tendencies began to appear in the Moscow principality. Inside the Russian church, several areas were distinguished. Part of the clergy supported the specificobar form. The other understood the need for transformations in society. As a result, this led to a split in the Russian church in the 15th century for "non-possessors" and "Josephites". The former linked the fate of the future with the ideology of hesychasm and its moral transformation, while the latter sought support in alliance with a strong secular power.


2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.


Moreana ◽  
2017 ◽  
Vol 54 (Number 207) (1) ◽  
pp. 36-56
Author(s):  
Gerard Wegemer

After establishing a context of More's lifelong engagement with the “calculus” of pleasure, this essay shows how the section devoted to the Utopians' pleasure philosophy is structured around five formulations of a “rule” to calculate “true and honest [honesta]” pleasure in ways that playfully imitate and echo the “rule” Cicero formulates several times in De officiis to discern one's duty when there seems to be a conflict between honestas et utilitas. When followed, the Utopian pleasure calculus shows the necessary role of societas, officii, iustitia, caritas, and the other aspects of human nature, most importantly friendship, that Cicero stresses in his rule and that he argued Epicurus ignored. Much of the irony and humor of this section depends on seeing the predominance of Ciceronian vocabulary in Raphael's unusual defense [patrocinium] of pleasure, rather than a Ciceronian defense of duty rooted in honestas. Throughout, however, this essay also shows how More goes beyond Cicero by including Augustinian and biblical allusions to suggest ways that our final end is not as Epicurus or the Stoics or Cicero claim; the language and allusions of this section point to a level of good cheer and care for neighbors and for God in ways quite different from any classical thinker.


1973 ◽  
Vol 74 (4) ◽  
pp. 769-774 ◽  
Author(s):  
Akira Yokoyama ◽  
Hiroshi Tomogane ◽  
Katuaki Ôta
Keyword(s):  

ABSTRACT A non-steroidal oestrogen antagonist, MER-25, was administered to cycling rats for elucidating the role of oestrogen in the surge of prolactin observed on the afternoon of pro-oestrus (POe). In animals injected with 20 mg of MER-25 intramuscularly on the afternoon (16.30 h) of the first day of dioestrus (D-1), the surge of prolactin was blocked while the level of prolactin on the afternoon of POe of these animals was significantly higher than that of the corresponding controls injected with oil. Ovulation was also blocked in these animals treated with the drug on the afternoon of D-l. On the other hand, treatment on the morning (10.30 h) of the 2nd day of dioestrus failed to prevent not only the surge of prolactin but also ovulation. These observations provide strong evidence for the view that oestrogen is responsible for the surge of prolactin on the afternoon of POe, and that the surge is accompanied by that of LH.


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