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The UDP-glucose: glycoprotein glucosyltransferase (UGGT), a key enzyme in ER quality control, plays a significant role in plant growth as well as biotic and abiotic stress in Arabidopsis thaliana.

Blanco-Herrera F, Moreno AA, Tapia R, Reyes F, Araya M, D'Alessio C, Parodi A, Orellana A - BMC Plant Biol. (2015)

Bottom Line: Here, we show that two mutant alleles in the At1g71220 locus have none or reduced UGGT activity.These results show that a lack of UGGT activity alters plant vegetative development and impairs the response to several abiotic and biotic stresses.Moreover, our results uncover an unexpected role of UGGT in the incorporation of UDP-Glucose into the ER lumen in Arabidopsis thaliana.

View Article: PubMed Central - PubMed

Affiliation: Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Avenida República 217, Santiago, 837-0146, RM, Chile. mblanco@unab.cl.

ABSTRACT

Background: UDP-glucose: glycoprotein glucosyltransferase (UGGT) is a key player in the quality control mechanism (ER-QC) that newly synthesized glycoproteins undergo in the ER. It has been shown that the UGGT Arabidopsis orthologue is involved in ER-QC; however, its role in plant physiology remains unclear.

Results: Here, we show that two mutant alleles in the At1g71220 locus have none or reduced UGGT activity. In wild type plants, the AtUGGT transcript levels increased upon activation of the unfolded protein response (UPR). Interestingly, mutants in AtUGGT exhibited an endogenous up-regulation of genes that are UPR targets. In addition, mutants in AtUGGT showed a 30% reduction in the incorporation of UDP-Glucose into the ER suggesting that this enzyme drives the uptake of this substrate for the CNX/CRT cycle. Plants deficient in UGGT exhibited a delayed growth rate of the primary root and rosette as well as an alteration in the number of leaves. These mutants are more sensitive to pathogen attack as well as heat, salt, and UPR-inducing stressors. Additionally, the plants showed impairment in the establishment of systemic acquired resistance (SAR).

Conclusions: These results show that a lack of UGGT activity alters plant vegetative development and impairs the response to several abiotic and biotic stresses. Moreover, our results uncover an unexpected role of UGGT in the incorporation of UDP-Glucose into the ER lumen in Arabidopsis thaliana.

No MeSH data available.


Related in: MedlinePlus

AtUGGT mutant plants are less tolerant to heat shock stress. Arabidopsis wild type and UGGT mutant plants were grown on soil for six weeks. The plants were treated at 42 °C for 2 hrs and returned to the growth chamber for 24 hrs. The leaves were then analyzed and classified as “dead” (completely dry and collapsed leaves), “damaged” (chlorotic lesions in leaves) or “healthy” (green and turgid leaves) and counted. The results are expressed as a percentage of total leaves analyzed per genotype (around 60 leaves per genotype)
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Fig7: AtUGGT mutant plants are less tolerant to heat shock stress. Arabidopsis wild type and UGGT mutant plants were grown on soil for six weeks. The plants were treated at 42 °C for 2 hrs and returned to the growth chamber for 24 hrs. The leaves were then analyzed and classified as “dead” (completely dry and collapsed leaves), “damaged” (chlorotic lesions in leaves) or “healthy” (green and turgid leaves) and counted. The results are expressed as a percentage of total leaves analyzed per genotype (around 60 leaves per genotype)

Mentions: We also investigated whether mutants in AtUGGT are more sensitive to abiotic stresses such as heat and salt because they have been shown to up-regulate ER chaperones associated with ERQC; mutants of the ERQC components also show a salt-sensitive phenotype [19–22]. Fig. 7 shows that mutant plants heat-shocked for 2 hrs at 42 °C and then returned to normal temperature developed a higher percentage of dead leaves and more chlorotic and necrotic lesions than wild type plants (Additional file 6). Furthermore, when grown at 150 mM NaCl, mutants were more sensitive than wild type plants (Fig. 8a) and displayed a significant decrease in fresh weight (Fig. 8b).Fig. 7


The UDP-glucose: glycoprotein glucosyltransferase (UGGT), a key enzyme in ER quality control, plays a significant role in plant growth as well as biotic and abiotic stress in Arabidopsis thaliana.

Blanco-Herrera F, Moreno AA, Tapia R, Reyes F, Araya M, D'Alessio C, Parodi A, Orellana A - BMC Plant Biol. (2015)

AtUGGT mutant plants are less tolerant to heat shock stress. Arabidopsis wild type and UGGT mutant plants were grown on soil for six weeks. The plants were treated at 42 °C for 2 hrs and returned to the growth chamber for 24 hrs. The leaves were then analyzed and classified as “dead” (completely dry and collapsed leaves), “damaged” (chlorotic lesions in leaves) or “healthy” (green and turgid leaves) and counted. The results are expressed as a percentage of total leaves analyzed per genotype (around 60 leaves per genotype)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4465474&req=5

Fig7: AtUGGT mutant plants are less tolerant to heat shock stress. Arabidopsis wild type and UGGT mutant plants were grown on soil for six weeks. The plants were treated at 42 °C for 2 hrs and returned to the growth chamber for 24 hrs. The leaves were then analyzed and classified as “dead” (completely dry and collapsed leaves), “damaged” (chlorotic lesions in leaves) or “healthy” (green and turgid leaves) and counted. The results are expressed as a percentage of total leaves analyzed per genotype (around 60 leaves per genotype)
Mentions: We also investigated whether mutants in AtUGGT are more sensitive to abiotic stresses such as heat and salt because they have been shown to up-regulate ER chaperones associated with ERQC; mutants of the ERQC components also show a salt-sensitive phenotype [19–22]. Fig. 7 shows that mutant plants heat-shocked for 2 hrs at 42 °C and then returned to normal temperature developed a higher percentage of dead leaves and more chlorotic and necrotic lesions than wild type plants (Additional file 6). Furthermore, when grown at 150 mM NaCl, mutants were more sensitive than wild type plants (Fig. 8a) and displayed a significant decrease in fresh weight (Fig. 8b).Fig. 7

Bottom Line: Here, we show that two mutant alleles in the At1g71220 locus have none or reduced UGGT activity.These results show that a lack of UGGT activity alters plant vegetative development and impairs the response to several abiotic and biotic stresses.Moreover, our results uncover an unexpected role of UGGT in the incorporation of UDP-Glucose into the ER lumen in Arabidopsis thaliana.

View Article: PubMed Central - PubMed

Affiliation: Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Avenida República 217, Santiago, 837-0146, RM, Chile. mblanco@unab.cl.

ABSTRACT

Background: UDP-glucose: glycoprotein glucosyltransferase (UGGT) is a key player in the quality control mechanism (ER-QC) that newly synthesized glycoproteins undergo in the ER. It has been shown that the UGGT Arabidopsis orthologue is involved in ER-QC; however, its role in plant physiology remains unclear.

Results: Here, we show that two mutant alleles in the At1g71220 locus have none or reduced UGGT activity. In wild type plants, the AtUGGT transcript levels increased upon activation of the unfolded protein response (UPR). Interestingly, mutants in AtUGGT exhibited an endogenous up-regulation of genes that are UPR targets. In addition, mutants in AtUGGT showed a 30% reduction in the incorporation of UDP-Glucose into the ER suggesting that this enzyme drives the uptake of this substrate for the CNX/CRT cycle. Plants deficient in UGGT exhibited a delayed growth rate of the primary root and rosette as well as an alteration in the number of leaves. These mutants are more sensitive to pathogen attack as well as heat, salt, and UPR-inducing stressors. Additionally, the plants showed impairment in the establishment of systemic acquired resistance (SAR).

Conclusions: These results show that a lack of UGGT activity alters plant vegetative development and impairs the response to several abiotic and biotic stresses. Moreover, our results uncover an unexpected role of UGGT in the incorporation of UDP-Glucose into the ER lumen in Arabidopsis thaliana.

No MeSH data available.


Related in: MedlinePlus