Limits...
Characterization of VuMATE1 Expression in Response to Iron Nutrition and Aluminum Stress Reveals Adaptation of Rice Bean (Vigna umbellata) to Acid Soils through Cis Regulation.

Liu M, Xu J, Lou H, Fan W, Yang J, Zheng S - Front Plant Sci (2016)

Bottom Line: The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status.We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition.These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acid soils where Al stress imposed but Fe deficiency pressure released.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang UniversityHangzhou, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural SciencesHangzhou, China.

ABSTRACT
Rice bean (Vigna umbellata) VuMATE1 appears to be constitutively expressed at vascular system but root apex, and Al stress extends its expression to root apex. Whether VuMATE1 participates in both Al tolerance and Fe nutrition, and how VuMATE1 expression is regulated is of great interest. In this study, the role of VuMATE1 in Fe nutrition was characterized through in planta complementation assays. The transcriptional regulation of VuMATE1 was investigated through promoter analysis and promoter-GUS reporter assays. The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status. Complementation of frd3-1 with VuMATE1 under VuMATE1 promoter could not restore phenotype, but restored with 35SCaMV promoter. Immunostaining of VuMATE1 revealed abnormal localization of VuMATE1 in vasculature. In planta GUS reporter assay identified Al-responsive cis-acting elements resided between -1228 and -574 bp. Promoter analysis revealed several cis-acting elements, but transcription is not simply regulated by one of these elements. We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition. These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acid soils where Al stress imposed but Fe deficiency pressure released.

No MeSH data available.


Related in: MedlinePlus

In planta complementation assay of VuMATE1 in Fe nutrition in Arabidopsis mutant frd3-1 driven by its native promoter (VuMATE1p::VuMATE1/frd3-1). (A) RT-PCR characterization of VuMATE1 expression in roots of two independent complemented lines (line 1 and line 2). (B) Phenotype analysis of leaf chlorosis in wild-type (WT), frd3-1, and two complemented lines. (C) Chlorophyll content of newly expanded leaves in wild-type (WT), frd3-1, and two complemented lines. Data are expressed as means ± SD (n = 4). Columns with different letters are significantly different at P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835453&req=5

Figure 2: In planta complementation assay of VuMATE1 in Fe nutrition in Arabidopsis mutant frd3-1 driven by its native promoter (VuMATE1p::VuMATE1/frd3-1). (A) RT-PCR characterization of VuMATE1 expression in roots of two independent complemented lines (line 1 and line 2). (B) Phenotype analysis of leaf chlorosis in wild-type (WT), frd3-1, and two complemented lines. (C) Chlorophyll content of newly expanded leaves in wild-type (WT), frd3-1, and two complemented lines. Data are expressed as means ± SD (n = 4). Columns with different letters are significantly different at P < 0.05.

Mentions: The localization of VuMATE1 to the vascular system prompted us to investigate whether VuMATE1 is also involved in Fe nutrition similar to HvAACT1 in barley (Fujii et al., 2012) and TaMATE1B in wheat (Tovkach et al., 2013). We expressed VuMATE1 using its native promoter in the Arabidopsis mutant frd3-1 (VuMATE1p::VuMATE1/frd3-1), which is defective in Fe translocation (Green and Rogers, 2004), and two independent transgenic lines (line1 and line2) were used for further analysis. RT-PCR analysis indicated that VuMATE1 was expressed in both transgenic lines but not in frd3-1 mutant (Figure 2A). When grown in one-fifth-strength Hoagland nutrient solution, newly expanded leaves of the frd3-1 mutant lines exhibited severe chlorosis (Figure 2B), which is in accordance with lower chlorophyll levels (Figure 2C). Perls blue staining demonstrated that significantly more Fe was accumulated in the root vasculature of frd3-1 than WT plants (Supplementary Figure S4), which is consistent with previous descriptions of this mutant (Durrett et al., 2007). The frd3-1 lines transformed with VuMATE1p::VuMATE1 showed these same general symptoms (Figure 2B). Chlorophyll content of the newly expanded leaves in frd3-1 and the two independent complementation lines was approximately half of WT levels (Figure 2C). Perls blue staining of roots showed similarly high Fe precipitation in the vasculature of the complementation lines (Supplementary Figure S4), indicating that Fe translocation to the shoots was reduced in all the lines. These results indicate that VuMATE1 expression driven by its native promoter could not complement the mutant phenotype of frd3-1.


Characterization of VuMATE1 Expression in Response to Iron Nutrition and Aluminum Stress Reveals Adaptation of Rice Bean (Vigna umbellata) to Acid Soils through Cis Regulation.

Liu M, Xu J, Lou H, Fan W, Yang J, Zheng S - Front Plant Sci (2016)

In planta complementation assay of VuMATE1 in Fe nutrition in Arabidopsis mutant frd3-1 driven by its native promoter (VuMATE1p::VuMATE1/frd3-1). (A) RT-PCR characterization of VuMATE1 expression in roots of two independent complemented lines (line 1 and line 2). (B) Phenotype analysis of leaf chlorosis in wild-type (WT), frd3-1, and two complemented lines. (C) Chlorophyll content of newly expanded leaves in wild-type (WT), frd3-1, and two complemented lines. Data are expressed as means ± SD (n = 4). Columns with different letters are significantly different at P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835453&req=5

Figure 2: In planta complementation assay of VuMATE1 in Fe nutrition in Arabidopsis mutant frd3-1 driven by its native promoter (VuMATE1p::VuMATE1/frd3-1). (A) RT-PCR characterization of VuMATE1 expression in roots of two independent complemented lines (line 1 and line 2). (B) Phenotype analysis of leaf chlorosis in wild-type (WT), frd3-1, and two complemented lines. (C) Chlorophyll content of newly expanded leaves in wild-type (WT), frd3-1, and two complemented lines. Data are expressed as means ± SD (n = 4). Columns with different letters are significantly different at P < 0.05.
Mentions: The localization of VuMATE1 to the vascular system prompted us to investigate whether VuMATE1 is also involved in Fe nutrition similar to HvAACT1 in barley (Fujii et al., 2012) and TaMATE1B in wheat (Tovkach et al., 2013). We expressed VuMATE1 using its native promoter in the Arabidopsis mutant frd3-1 (VuMATE1p::VuMATE1/frd3-1), which is defective in Fe translocation (Green and Rogers, 2004), and two independent transgenic lines (line1 and line2) were used for further analysis. RT-PCR analysis indicated that VuMATE1 was expressed in both transgenic lines but not in frd3-1 mutant (Figure 2A). When grown in one-fifth-strength Hoagland nutrient solution, newly expanded leaves of the frd3-1 mutant lines exhibited severe chlorosis (Figure 2B), which is in accordance with lower chlorophyll levels (Figure 2C). Perls blue staining demonstrated that significantly more Fe was accumulated in the root vasculature of frd3-1 than WT plants (Supplementary Figure S4), which is consistent with previous descriptions of this mutant (Durrett et al., 2007). The frd3-1 lines transformed with VuMATE1p::VuMATE1 showed these same general symptoms (Figure 2B). Chlorophyll content of the newly expanded leaves in frd3-1 and the two independent complementation lines was approximately half of WT levels (Figure 2C). Perls blue staining of roots showed similarly high Fe precipitation in the vasculature of the complementation lines (Supplementary Figure S4), indicating that Fe translocation to the shoots was reduced in all the lines. These results indicate that VuMATE1 expression driven by its native promoter could not complement the mutant phenotype of frd3-1.

Bottom Line: The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status.We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition.These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acid soils where Al stress imposed but Fe deficiency pressure released.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang UniversityHangzhou, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural SciencesHangzhou, China.

ABSTRACT
Rice bean (Vigna umbellata) VuMATE1 appears to be constitutively expressed at vascular system but root apex, and Al stress extends its expression to root apex. Whether VuMATE1 participates in both Al tolerance and Fe nutrition, and how VuMATE1 expression is regulated is of great interest. In this study, the role of VuMATE1 in Fe nutrition was characterized through in planta complementation assays. The transcriptional regulation of VuMATE1 was investigated through promoter analysis and promoter-GUS reporter assays. The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status. Complementation of frd3-1 with VuMATE1 under VuMATE1 promoter could not restore phenotype, but restored with 35SCaMV promoter. Immunostaining of VuMATE1 revealed abnormal localization of VuMATE1 in vasculature. In planta GUS reporter assay identified Al-responsive cis-acting elements resided between -1228 and -574 bp. Promoter analysis revealed several cis-acting elements, but transcription is not simply regulated by one of these elements. We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition. These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acid soils where Al stress imposed but Fe deficiency pressure released.

No MeSH data available.


Related in: MedlinePlus