Limits...
The Arabidopsis PLAT domain protein1 is critically involved in abiotic stress tolerance.

Hyun TK, van der Graaff E, Albacete A, Eom SH, Großkinsky DK, Böhm H, Janschek U, Rim Y, Ali WW, Kim SY, Roitsch T - PLoS ONE (2014)

Bottom Line: PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance.This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway.The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Sciences, University of Graz, Graz, Austria; Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.

ABSTRACT
Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions. Abiotic stress treatments induced PLAT1 expression and caused expansion of its expression domain. The ABF/ABRE transcription factors, which are positive mediators of abscisic acid signalling, activate PLAT1 promoter activity in transactivation assays and directly bind to the ABRE elements located in this promoter in electrophoretic mobility shift assays. This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway. Thus, we showed that PLAT1 critically functions as positive regulator of abiotic stress tolerance, but also is involved in regulating plant growth, and thereby assigned a function to this previously uncharacterised PLAT domain protein. The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.

Show MeSH

Related in: MedlinePlus

PLAT1 promotes plant growth.Phenotypes of plants from control medium including 5 µM DEX from the salt stress experiment shown in Figure 3. (A) Wild-type. (B) plat1-1. (C-E) Three independent PLAT1 ectopic overexpression lines (OX). Scale bar = 1 cm. (F) Shoot biomass production (weight per 5 shoots) for the different PLAT1 lines. Values are means of 8 replicates ± standard deviation. ***, ** or * indicate statistical significance calculated using the unpaired Student's t-test at p<0.001, p<0.01 or p<0.05, respectively.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4232524&req=5

pone-0112946-g005: PLAT1 promotes plant growth.Phenotypes of plants from control medium including 5 µM DEX from the salt stress experiment shown in Figure 3. (A) Wild-type. (B) plat1-1. (C-E) Three independent PLAT1 ectopic overexpression lines (OX). Scale bar = 1 cm. (F) Shoot biomass production (weight per 5 shoots) for the different PLAT1 lines. Values are means of 8 replicates ± standard deviation. ***, ** or * indicate statistical significance calculated using the unpaired Student's t-test at p<0.001, p<0.01 or p<0.05, respectively.

Mentions: The DEX induced PLAT1 OX lines from the salt stress experiment shown in Figure 3, appeared to show faster development on control medium including DEX (Figure 5A-E). Therefore, shoot and root growth was analysed in the plat1-1 mutant and PLAT1 overexpression lines. This showed that the different PLAT1 overexpression lines produced more shoot biomass compared to wild-type control (Figure 5F), while the length of the root apical meristem and total root length were not affected (Table S5 in File S1). Interestingly, the number of emerged lateral roots was increased, but only for the ectopic PLAT1 (OX) overexpression lines (Table S5 in File S1). This effect on lateral root formation was the only difference observed between the tissue specific and ectopic overexpression lines, and could reflect the difference between increased expression at its natural expression site (GUS and YFP) and broader expression in new (ectopic) cell types (OX). In contrast, PLAT1 loss-of-function did not affect either shoot or root growth, except for a reduced number of emerged lateral roots (Figure 5F, Table S5 in File S1).


The Arabidopsis PLAT domain protein1 is critically involved in abiotic stress tolerance.

Hyun TK, van der Graaff E, Albacete A, Eom SH, Großkinsky DK, Böhm H, Janschek U, Rim Y, Ali WW, Kim SY, Roitsch T - PLoS ONE (2014)

PLAT1 promotes plant growth.Phenotypes of plants from control medium including 5 µM DEX from the salt stress experiment shown in Figure 3. (A) Wild-type. (B) plat1-1. (C-E) Three independent PLAT1 ectopic overexpression lines (OX). Scale bar = 1 cm. (F) Shoot biomass production (weight per 5 shoots) for the different PLAT1 lines. Values are means of 8 replicates ± standard deviation. ***, ** or * indicate statistical significance calculated using the unpaired Student's t-test at p<0.001, p<0.01 or p<0.05, respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232524&req=5

pone-0112946-g005: PLAT1 promotes plant growth.Phenotypes of plants from control medium including 5 µM DEX from the salt stress experiment shown in Figure 3. (A) Wild-type. (B) plat1-1. (C-E) Three independent PLAT1 ectopic overexpression lines (OX). Scale bar = 1 cm. (F) Shoot biomass production (weight per 5 shoots) for the different PLAT1 lines. Values are means of 8 replicates ± standard deviation. ***, ** or * indicate statistical significance calculated using the unpaired Student's t-test at p<0.001, p<0.01 or p<0.05, respectively.
Mentions: The DEX induced PLAT1 OX lines from the salt stress experiment shown in Figure 3, appeared to show faster development on control medium including DEX (Figure 5A-E). Therefore, shoot and root growth was analysed in the plat1-1 mutant and PLAT1 overexpression lines. This showed that the different PLAT1 overexpression lines produced more shoot biomass compared to wild-type control (Figure 5F), while the length of the root apical meristem and total root length were not affected (Table S5 in File S1). Interestingly, the number of emerged lateral roots was increased, but only for the ectopic PLAT1 (OX) overexpression lines (Table S5 in File S1). This effect on lateral root formation was the only difference observed between the tissue specific and ectopic overexpression lines, and could reflect the difference between increased expression at its natural expression site (GUS and YFP) and broader expression in new (ectopic) cell types (OX). In contrast, PLAT1 loss-of-function did not affect either shoot or root growth, except for a reduced number of emerged lateral roots (Figure 5F, Table S5 in File S1).

Bottom Line: PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance.This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway.The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Sciences, University of Graz, Graz, Austria; Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.

ABSTRACT
Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions. Abiotic stress treatments induced PLAT1 expression and caused expansion of its expression domain. The ABF/ABRE transcription factors, which are positive mediators of abscisic acid signalling, activate PLAT1 promoter activity in transactivation assays and directly bind to the ABRE elements located in this promoter in electrophoretic mobility shift assays. This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway. Thus, we showed that PLAT1 critically functions as positive regulator of abiotic stress tolerance, but also is involved in regulating plant growth, and thereby assigned a function to this previously uncharacterised PLAT domain protein. The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.

Show MeSH
Related in: MedlinePlus