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Alternative Strategies in Response to Saline Stress in Two Varieties of Portulaca oleracea (Purslane).

Mulry KR, Hanson BA, Dudle DA - PLoS ONE (2015)

Bottom Line: The varieties responded to saline stress with significantly different changes in the measured traits, which included inter alia biomass, flower counts, proline concentrations and betalain pigment concentrations.Taken holistically, our results suggest that the two varieties employ different strategies in allocating resources to cope with saline stress.This conclusion establishes purslane as a suitable model system for the study of saline stress and the molecular basis for differential responses.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Chemistry & Biochemistry, DePauw University, Greencastle, Indiana, United States of America.

ABSTRACT
Purslane (Portulaca oleracea) is a globally-distributed plant with a long history of use in folk medicine and cooking. We have developed purslane as a model system for exploring plant responses to stress. We exposed two varieties of purslane to saline stress with the objective of identifying differences between the varieties in the plasticity of morphological and physiological traits. The varieties responded to saline stress with significantly different changes in the measured traits, which included inter alia biomass, flower counts, proline concentrations and betalain pigment concentrations. The alternative responses of the two varieties consisted of complex, simultaneous changes in multiple traits. In particular, we observed that while both varieties increased production of betalain pigments and proline under saline stress, one variety invested more in betalain pigments while the other invested more in proline. Proline and betalain pigments undoubtedly play multiple roles in plant tissues, but in this case their role as antioxidants deployed to ameliorate saline stress appears to be important. Taken holistically, our results suggest that the two varieties employ different strategies in allocating resources to cope with saline stress. This conclusion establishes purslane as a suitable model system for the study of saline stress and the molecular basis for differential responses.

No MeSH data available.


Morphological traits at 21 days.Variety T-16 shown in green. Variety WI-9 shown in red. Large point is the mean of the category. Small points are the sample values, jittered horizontally. Error bars correspond to the 95% confidence interval.
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pone.0138723.g002: Morphological traits at 21 days.Variety T-16 shown in green. Variety WI-9 shown in red. Large point is the mean of the category. Small points are the sample values, jittered horizontally. Error bars correspond to the 95% confidence interval.

Mentions: At the end of the 14-day establishment period, ANOVA was used to verify that the seedlings assigned to each treatment were similar within a variety, prior to the actual start of treatments (data not shown). Fig 2 shows the variation in morphological traits with saline stress after 21 days of treatment. There were significant variety by treatment interactions for all variables (Table 1). Both varieties produced fewer flowers and less dry biomass under saline stress. The decrease in flowering structures was particularly dramatic for variety WI-9. Variety T-16 produced fewer nodes and dropped more leaves from the main stem under the saline treatment than variety WI-9. However, variety WI-9 showed little change for these two variables under saline stress (see also S1, S2 and S3 Figs).


Alternative Strategies in Response to Saline Stress in Two Varieties of Portulaca oleracea (Purslane).

Mulry KR, Hanson BA, Dudle DA - PLoS ONE (2015)

Morphological traits at 21 days.Variety T-16 shown in green. Variety WI-9 shown in red. Large point is the mean of the category. Small points are the sample values, jittered horizontally. Error bars correspond to the 95% confidence interval.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4580602&req=5

pone.0138723.g002: Morphological traits at 21 days.Variety T-16 shown in green. Variety WI-9 shown in red. Large point is the mean of the category. Small points are the sample values, jittered horizontally. Error bars correspond to the 95% confidence interval.
Mentions: At the end of the 14-day establishment period, ANOVA was used to verify that the seedlings assigned to each treatment were similar within a variety, prior to the actual start of treatments (data not shown). Fig 2 shows the variation in morphological traits with saline stress after 21 days of treatment. There were significant variety by treatment interactions for all variables (Table 1). Both varieties produced fewer flowers and less dry biomass under saline stress. The decrease in flowering structures was particularly dramatic for variety WI-9. Variety T-16 produced fewer nodes and dropped more leaves from the main stem under the saline treatment than variety WI-9. However, variety WI-9 showed little change for these two variables under saline stress (see also S1, S2 and S3 Figs).

Bottom Line: The varieties responded to saline stress with significantly different changes in the measured traits, which included inter alia biomass, flower counts, proline concentrations and betalain pigment concentrations.Taken holistically, our results suggest that the two varieties employ different strategies in allocating resources to cope with saline stress.This conclusion establishes purslane as a suitable model system for the study of saline stress and the molecular basis for differential responses.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Chemistry & Biochemistry, DePauw University, Greencastle, Indiana, United States of America.

ABSTRACT
Purslane (Portulaca oleracea) is a globally-distributed plant with a long history of use in folk medicine and cooking. We have developed purslane as a model system for exploring plant responses to stress. We exposed two varieties of purslane to saline stress with the objective of identifying differences between the varieties in the plasticity of morphological and physiological traits. The varieties responded to saline stress with significantly different changes in the measured traits, which included inter alia biomass, flower counts, proline concentrations and betalain pigment concentrations. The alternative responses of the two varieties consisted of complex, simultaneous changes in multiple traits. In particular, we observed that while both varieties increased production of betalain pigments and proline under saline stress, one variety invested more in betalain pigments while the other invested more in proline. Proline and betalain pigments undoubtedly play multiple roles in plant tissues, but in this case their role as antioxidants deployed to ameliorate saline stress appears to be important. Taken holistically, our results suggest that the two varieties employ different strategies in allocating resources to cope with saline stress. This conclusion establishes purslane as a suitable model system for the study of saline stress and the molecular basis for differential responses.

No MeSH data available.