Effects of Mineral Nutrition on Endogenous Cytokinins in Plants of Sunflower (<i>Helianthus annuus</i>L.)

Eid, Abdel-Fattah M.; Salama, A.; Wareing, P. F.

doi:10.1093/jxb/30.5.971

Cited by 161 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In addition to changes in sodium ions, some of the cytokinin mutants examined showed alterations in the levels of other ions relative to wild‐type controls. This was not entirely unexpected as cytokinin has been reported to regulate gene expression in response to alterations in the levels of several nutrients, including sulfur, phosphate and nitrogen (Ei‐D et al. , 1979; Takei et al.…”

Section: Resultsmentioning

confidence: 82%

“…These results are consistent with a role for cytokinin in regulating sodium accumulation, possibly by modulating the transport of sodium ions to the shoot. The ability of cytokinin to regulate sodium accumulation is reminiscent of the previously described roles of cytokinin in regulating phosphate, sulfur and nitrogen levels by altering the expression of genes involved in their respective ion‐specific starvation responses (Ei‐D et al. , 1979; Takei et al.…”

Section: Discussionmentioning

confidence: 93%

See 1 more Smart Citation

Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots

Mason¹,

Jha²,

Salt³

et al. 2010

The Plant Journal

141

View full text Add to dashboard Cite

SUMMARYSoil salinity affects a large proportion of the land worldwide, forcing plants to evolve a number of mechanisms to cope with salt stress. Cytokinin plays a role in the plant response to salt stress, but little is known about the mechanism by which cytokinin controls this process. We used a molecular genetics approach to examine the influence of cytokinin on sodium accumulation and salt sensitivity in Arabidopsis thaliana. Cytokinin application was found to increase sodium accumulation in the shoots of Arabidopsis, but had no significant affect on the sodium content in the roots. Consistent with this, altered sodium accumulation phenotypes were observed in mutants of each gene class of the cytokinin signal transduction pathway, including receptors, phospho-transfer proteins, and type-A and type-B response regulators. Expression of the gene encoding Arabidopsis high-affinity K + transporter 1;1 (AtHKT1;1), a gene responsible for removing sodium ions from the root xylem, was repressed by cytokinin treatment, but showed significantly elevated expression in the cytokinin response double mutant arr1-3 arr12-1. Our data suggest that cytokinin, acting through the transcription factors ARR1 and ARR12, regulates sodium accumulation in the shoots by controlling the expression of AtHKT1;1 in the roots.

show abstract

Section: Resultsmentioning

confidence: 82%

Section: Discussionmentioning

confidence: 93%

Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots

Mason¹,

Jha²,

Salt³

et al. 2010

The Plant Journal

141

View full text Add to dashboard Cite

show abstract

“…that the loss of CRE1 leads to loss of miR171h induction by cytokinins. Because it is known that P i and nitrogen fertilization increases cytokinin levels of plants [[47],[48]] and elevated levels are also found in shoots and roots of mycorrhizal plants [reviewed in 35]. Based on this knowledge we hypothesized that the expression levels of miR171h at high phosphate conditions might be dependent on CRE1 as a direct effect of induced cytokinin levels in these plants.…”

Section: Discussionmentioning

confidence: 99%

MiR171h restricts root symbioses and shows like its target NSP2 a complex transcriptional regulation in Medicago truncatula

et al. 2014

View full text Add to dashboard Cite

BackgroundLegumes have the unique capability to undergo root nodule and arbuscular mycorrhizal symbiosis. Both types of root endosymbiosis are regulated by NSP2, which is a target of microRNA171h (miR171h). Although, recent data implies that miR171h specifically restricts arbuscular mycorrhizal symbiosis in the root elongation zone of Medicago truncatula roots, there is limited knowledge available about the spatio-temporal regulation of miR171h expression at different physiological and symbiotic conditions.ResultsWe show that miR171h is functionally expressed from an unusual long primary transcript, previously predicted to encode two identical miR171h strands. Both miR171h and NSP2 transcripts display a complex regulation pattern, which involves the symbiotic status and the fertilization regime of the plant. Quantitative Real-time PCR revealed that miR171h and NSP2 transcript levels show a clear anti-correlation in all tested conditions except in mycorrhizal roots, where NSP2 transcript levels were induced despite of an increased miR171h expression. This was also supported by a clear correlation of transcript levels of NSP2 and MtPt4, a phosphate transporter specifically expressed in a functional AM symbiosis. MiR171h is strongly induced in plants growing in sufficient phosphate conditions, which we demonstrate to be independent of the CRE1 signaling pathway and which is also not required for transcriptional induction of NSP2 in mycorrhizal roots. In situ hybridization and promoter activity analysis of both genes confirmed the complex regulation involving the symbiotic status, P and N nutrition, where both genes show a mainly mutual exclusive expression pattern. Overexpression of miR171h in M. truncatula roots led to a reduction in mycorrhizal colonization and to a reduced nodulation by Sinorhizobium meliloti.ConclusionThe spatio-temporal expression of miR171h and NSP2 is tightly linked to the nutritional status of the plant and, together with the results from the overexpression analysis, points to an important function of miR171h to integrate the nutrient homeostasis in order to safeguard the expression domain of NSP2 during both, arbuscular mycorrhizal and root nodule symbiosis.

show abstract

“…Conversely to the effect of CK in PSR, Pi-limiting conditions repressed accumulation of CK and expression of CRE1 gene, although the mechanism by which this occurs remains an open question (Franco-Zorrilla et al 2002;Salama and Wareing 1979). Concomitant reduction of CK concentration and sensitivity, due to reduced CRE1 levels, should favor full responsiveness of plants to this nutritional stress, including increased reallocation of biomass to the roots (Hermans et al 2006).…”

Section: Cytokinins (Ck)mentioning

confidence: 99%

Plant hormones and nutrient signaling

et al. 2008

View full text Add to dashboard Cite

Plants count on a wide variety of metabolic, physiological, and developmental responses to adapt their growth to variations in mineral nutrient availability. To react to such variations plants have evolved complex sensing and signaling mechanisms that allow them to monitor the external and internal concentration of each of these nutrients, both in absolute terms and also relatively to the status of other nutrients. Recent evidence has shown that hormones participate in the control of these regulatory networks. Conversely, mineral nutrient conditions influence hormone biosynthesis, further supporting close interrelation between hormonal stimuli and nutritional homeostasis. In this review, we summarize these evidences and analyze possible transcriptional correlations between hormonal and nutritional responses, as a means to further characterize the role of hormones in the response of plants to limiting nutrients in soil.

show abstract

Effects of Mineral Nutrition on Endogenous Cytokinins in Plants of Sunflower (Helianthus annuusL.)

Cited by 161 publications

References 0 publications

Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots

Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots

MiR171h restricts root symbioses and shows like its target NSP2 a complex transcriptional regulation in Medicago truncatula

Plant hormones and nutrient signaling

Contact Info

Product

Resources

About