Limits...
WRKY6 restricts Piriformospora indica-stimulated and phosphate-induced root development in Arabidopsis.

Bakshi M, Vahabi K, Bhattacharya S, Sherameti I, Varma A, Yeh KW, Baldwin I, Johri AK, Oelmüller R - BMC Plant Biol. (2015)

Bottom Line: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant.This is associated with the stimulation of PHOSPHATE1 expression and ethylene production.They can be tested for optimizing root growth in model and agricultural plants.

View Article: PubMed Central - PubMed

Affiliation: Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburgerstr. 159, D-07743, Jena, Germany. bakshi.madhunita@gmail.com.

ABSTRACT

Background: Arabidopsis root growth is stimulated by Piriformospora indica, phosphate limitation and inactivation of the WRKY6 transcription factor. Combinations of these factors induce unexpected alterations in root and shoot growth, root architecture and root gene expression profiles.

Results: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant. This is associated with the stimulation of PHOSPHATE1 expression and ethylene production. Expression profiles from the roots of wrky6 seedlings identified genes involved in hormone metabolism, transport, meristem, cell and plastid proliferation, and growth regulation. 25 miRNAs were also up-regulated in these roots. We generated and discuss here a list of common genes which are regulated in growing roots and which are common to all three growth stimuli investigated in this study.

Conclusion: Since root development of wrky6 plants exposed to P. indica under phosphate limitation is strongly promoted, we propose that common genes which respond to all three growth stimuli are central for the control of root growth and architecture. They can be tested for optimizing root growth in model and agricultural plants.

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Related in: MedlinePlus

a Phenotypes of adult WT and wrky6 plants grown in the absence or presence of P. indica on LP or NP. For growth conditions, cf. Methods and Results. b Typical view of Arabidopsis plants grown in expanded clay for 2 months. c Quantification of fresh weight in grams. d Quantification of shoot length in cm after long term interaction in expanded clay for 2 months. Data are based on 3 independent experiments with 5 plants each. Bars represent SEs. Asterisks indicate significant differences, as determined by Student’s paired t-test for two tailed distribution (** P ≤ 0.01; * P ≤ 0.05)
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Fig3: a Phenotypes of adult WT and wrky6 plants grown in the absence or presence of P. indica on LP or NP. For growth conditions, cf. Methods and Results. b Typical view of Arabidopsis plants grown in expanded clay for 2 months. c Quantification of fresh weight in grams. d Quantification of shoot length in cm after long term interaction in expanded clay for 2 months. Data are based on 3 independent experiments with 5 plants each. Bars represent SEs. Asterisks indicate significant differences, as determined by Student’s paired t-test for two tailed distribution (** P ≤ 0.01; * P ≤ 0.05)

Mentions: Phenotypic differences become more obvious after long term interaction of the symbionts in expanded clay. After 14 days of co-cultivation in Petri dishes, P. indica-colonized or mock-treated WT and wrky6 seedlings grown on NP (2.5 mM, normal Pi) or LP (0.25 mM, low Pi) media were transferred to expanded clay. After 2 weeks, the first differences were observed in the size, shape and area of the leaves (Fig. 3a). P. indica-colonized wrky6 seedlings were bigger under the two Pi concentrations, compared to seedlings on vertical agar plates. Although all plants showed Pi stress symptoms when grown under LP conditions for 2 months, the wrky6 line performed better than the WT, and this was even more pronounced in the presence of P. indica. In particular, after 2 months, a significant increase in fresh weight (Fig. 3b, c) and shoot length (Fig. 3d) was observed for P. indica-treated wrky6 seedlings (grown on NP medium) compared to the untreated control and the WT. This confirms that WRKY6 restricts P. indica-mediated growth promotion.Fig. 3


WRKY6 restricts Piriformospora indica-stimulated and phosphate-induced root development in Arabidopsis.

Bakshi M, Vahabi K, Bhattacharya S, Sherameti I, Varma A, Yeh KW, Baldwin I, Johri AK, Oelmüller R - BMC Plant Biol. (2015)

a Phenotypes of adult WT and wrky6 plants grown in the absence or presence of P. indica on LP or NP. For growth conditions, cf. Methods and Results. b Typical view of Arabidopsis plants grown in expanded clay for 2 months. c Quantification of fresh weight in grams. d Quantification of shoot length in cm after long term interaction in expanded clay for 2 months. Data are based on 3 independent experiments with 5 plants each. Bars represent SEs. Asterisks indicate significant differences, as determined by Student’s paired t-test for two tailed distribution (** P ≤ 0.01; * P ≤ 0.05)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4697310&req=5

Fig3: a Phenotypes of adult WT and wrky6 plants grown in the absence or presence of P. indica on LP or NP. For growth conditions, cf. Methods and Results. b Typical view of Arabidopsis plants grown in expanded clay for 2 months. c Quantification of fresh weight in grams. d Quantification of shoot length in cm after long term interaction in expanded clay for 2 months. Data are based on 3 independent experiments with 5 plants each. Bars represent SEs. Asterisks indicate significant differences, as determined by Student’s paired t-test for two tailed distribution (** P ≤ 0.01; * P ≤ 0.05)
Mentions: Phenotypic differences become more obvious after long term interaction of the symbionts in expanded clay. After 14 days of co-cultivation in Petri dishes, P. indica-colonized or mock-treated WT and wrky6 seedlings grown on NP (2.5 mM, normal Pi) or LP (0.25 mM, low Pi) media were transferred to expanded clay. After 2 weeks, the first differences were observed in the size, shape and area of the leaves (Fig. 3a). P. indica-colonized wrky6 seedlings were bigger under the two Pi concentrations, compared to seedlings on vertical agar plates. Although all plants showed Pi stress symptoms when grown under LP conditions for 2 months, the wrky6 line performed better than the WT, and this was even more pronounced in the presence of P. indica. In particular, after 2 months, a significant increase in fresh weight (Fig. 3b, c) and shoot length (Fig. 3d) was observed for P. indica-treated wrky6 seedlings (grown on NP medium) compared to the untreated control and the WT. This confirms that WRKY6 restricts P. indica-mediated growth promotion.Fig. 3

Bottom Line: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant.This is associated with the stimulation of PHOSPHATE1 expression and ethylene production.They can be tested for optimizing root growth in model and agricultural plants.

View Article: PubMed Central - PubMed

Affiliation: Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburgerstr. 159, D-07743, Jena, Germany. bakshi.madhunita@gmail.com.

ABSTRACT

Background: Arabidopsis root growth is stimulated by Piriformospora indica, phosphate limitation and inactivation of the WRKY6 transcription factor. Combinations of these factors induce unexpected alterations in root and shoot growth, root architecture and root gene expression profiles.

Results: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant. This is associated with the stimulation of PHOSPHATE1 expression and ethylene production. Expression profiles from the roots of wrky6 seedlings identified genes involved in hormone metabolism, transport, meristem, cell and plastid proliferation, and growth regulation. 25 miRNAs were also up-regulated in these roots. We generated and discuss here a list of common genes which are regulated in growing roots and which are common to all three growth stimuli investigated in this study.

Conclusion: Since root development of wrky6 plants exposed to P. indica under phosphate limitation is strongly promoted, we propose that common genes which respond to all three growth stimuli are central for the control of root growth and architecture. They can be tested for optimizing root growth in model and agricultural plants.

Show MeSH
Related in: MedlinePlus