Limits...
Loss of the Arabidopsis thaliana P₄-ATPase ALA3 reduces adaptability to temperature stresses and impairs vegetative, pollen, and ovule development.

McDowell SC, López-Marqués RL, Poulsen LR, Palmgren MG, Harper JF - PLoS ONE (2013)

Bottom Line: We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects.In-vitro pollen tube growth assays showed that ala3 pollen germinated ∼2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length.Together, these results support a model in which ALA3 functions to modify endomembranes in multiple cell types, enabling structural changes, or signaling functions that are critical in plants for normal development and adaptation to varied growth environments.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada, United States of America.

ABSTRACT
Members of the P4 subfamily of P-type ATPases are thought to help create asymmetry in lipid bilayers by flipping specific lipids between the leaflets of a membrane. This asymmetry is believed to be central to the formation of vesicles in the secretory and endocytic pathways. In Arabidopsis thaliana, a P4-ATPase associated with the trans-Golgi network (ALA3) was previously reported to be important for vegetative growth and reproductive success. Here we show that multiple phenotypes for ala3 knockouts are sensitive to growth conditions. For example, ala3 rosette size was observed to be dependent upon both temperature and soil, and varied between 40% and 80% that of wild-type under different conditions. We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects. In-vitro pollen tube growth assays showed that ala3 pollen germinated ∼2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length. In genetic crosses under conditions of hot days and cold nights, pollen fitness was reduced by at least 90-fold; from ∼18% transmission efficiency (unstressed) to less than 0.2% (stressed). Together, these results support a model in which ALA3 functions to modify endomembranes in multiple cell types, enabling structural changes, or signaling functions that are critical in plants for normal development and adaptation to varied growth environments.

Show MeSH

Related in: MedlinePlus

In-vitro assays show ala3 pollen tubes have delayed emergence, slow growth and shorter overall length.Pollen was placed on pistils, either from the corresponding genotype or from surrogate ms-1 plants, and the pistils were placed on pollen tube growth media. Pollen tubes growing out of the pistils were measured over a 24 h time course. Arrows represent time when buds were first observed. Lengths were reported for each time point as the average length of the 10 longest pollen tubes. Values and error bars represent the mean ± SE of three independent experiments for wild-type and ala3-1, and two independent experiments for ala3-2.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3646830&req=5

pone-0062577-g004: In-vitro assays show ala3 pollen tubes have delayed emergence, slow growth and shorter overall length.Pollen was placed on pistils, either from the corresponding genotype or from surrogate ms-1 plants, and the pistils were placed on pollen tube growth media. Pollen tubes growing out of the pistils were measured over a 24 h time course. Arrows represent time when buds were first observed. Lengths were reported for each time point as the average length of the 10 longest pollen tubes. Values and error bars represent the mean ± SE of three independent experiments for wild-type and ala3-1, and two independent experiments for ala3-2.

Mentions: To quantify growth defects associated with ala3 pollen, in-vitro growth assays were done with two independent alleles, ala3-1 and ala3-2, over a 24 h time course (Figure 4). With the in-vitro growth conditions used here (which included a stigma to promote germination), the ala3 pollen began to germinate approximately 2 h after wild-type. After a 24 h growth period, the overall length of ala3 pollen tubes was about 2-fold less than wild-type. At the point of maximum pollen tube growth rates, ala3 tubes were 2-fold slower than wild-type.


Loss of the Arabidopsis thaliana P₄-ATPase ALA3 reduces adaptability to temperature stresses and impairs vegetative, pollen, and ovule development.

McDowell SC, López-Marqués RL, Poulsen LR, Palmgren MG, Harper JF - PLoS ONE (2013)

In-vitro assays show ala3 pollen tubes have delayed emergence, slow growth and shorter overall length.Pollen was placed on pistils, either from the corresponding genotype or from surrogate ms-1 plants, and the pistils were placed on pollen tube growth media. Pollen tubes growing out of the pistils were measured over a 24 h time course. Arrows represent time when buds were first observed. Lengths were reported for each time point as the average length of the 10 longest pollen tubes. Values and error bars represent the mean ± SE of three independent experiments for wild-type and ala3-1, and two independent experiments for ala3-2.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646830&req=5

pone-0062577-g004: In-vitro assays show ala3 pollen tubes have delayed emergence, slow growth and shorter overall length.Pollen was placed on pistils, either from the corresponding genotype or from surrogate ms-1 plants, and the pistils were placed on pollen tube growth media. Pollen tubes growing out of the pistils were measured over a 24 h time course. Arrows represent time when buds were first observed. Lengths were reported for each time point as the average length of the 10 longest pollen tubes. Values and error bars represent the mean ± SE of three independent experiments for wild-type and ala3-1, and two independent experiments for ala3-2.
Mentions: To quantify growth defects associated with ala3 pollen, in-vitro growth assays were done with two independent alleles, ala3-1 and ala3-2, over a 24 h time course (Figure 4). With the in-vitro growth conditions used here (which included a stigma to promote germination), the ala3 pollen began to germinate approximately 2 h after wild-type. After a 24 h growth period, the overall length of ala3 pollen tubes was about 2-fold less than wild-type. At the point of maximum pollen tube growth rates, ala3 tubes were 2-fold slower than wild-type.

Bottom Line: We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects.In-vitro pollen tube growth assays showed that ala3 pollen germinated ∼2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length.Together, these results support a model in which ALA3 functions to modify endomembranes in multiple cell types, enabling structural changes, or signaling functions that are critical in plants for normal development and adaptation to varied growth environments.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada, United States of America.

ABSTRACT
Members of the P4 subfamily of P-type ATPases are thought to help create asymmetry in lipid bilayers by flipping specific lipids between the leaflets of a membrane. This asymmetry is believed to be central to the formation of vesicles in the secretory and endocytic pathways. In Arabidopsis thaliana, a P4-ATPase associated with the trans-Golgi network (ALA3) was previously reported to be important for vegetative growth and reproductive success. Here we show that multiple phenotypes for ala3 knockouts are sensitive to growth conditions. For example, ala3 rosette size was observed to be dependent upon both temperature and soil, and varied between 40% and 80% that of wild-type under different conditions. We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects. In-vitro pollen tube growth assays showed that ala3 pollen germinated ∼2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length. In genetic crosses under conditions of hot days and cold nights, pollen fitness was reduced by at least 90-fold; from ∼18% transmission efficiency (unstressed) to less than 0.2% (stressed). Together, these results support a model in which ALA3 functions to modify endomembranes in multiple cell types, enabling structural changes, or signaling functions that are critical in plants for normal development and adaptation to varied growth environments.

Show MeSH
Related in: MedlinePlus