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Growth and chlorophyll a fluorescence in Erythrina crista-galli L. plants under flooding conditions

100%

Larre C. F., Fernando J. A., Marini P., Bacarin M. A., Peters J. A.

Acta Physiologiae Plantarum

2013

tom 35

nr 05

The present study aimed to analyse the alterations in the growth and chlorophyll content of Erythrina crista-galli plants in response to flooding and to evaluate possible photosystem II (PSII) damage through chlorophyll a fluorescence transient analysis using the JIP test. Plants cultured from seeds were grown in 0.5-L pots in a greenhouse and transferred to 5-L pots. Two treatments were employed: plants were either flooded at the root and maintained with a sheet of water above the soil or not flooded (control). Evaluations were performed at 10, 20, 30 and 40 days after the treatment was initiated. The experiment was set up in a randomised block design, and the results were subjected to analysis of variance (ANOVA). The means were compared by Tukey’s test at a 5 % significance level. The flooding of the plants induced the formation of lenticels, adventitious roots and larger intercellular spaces in the root cortex and inhibited the growth of shoots at early time points compared to control plants. However, growth resumed by the end of the experimental period. The Erythrina crista-galli plants manifested a reduction in chlorophyll content as a function of the duration of exposure to flooding. However, there were changes in the chlorophyll fluorescence parameters, indicating impairment of the structure and function of PSII, and the performance indices were the most representative parameters to describe the effects of flooding. The results showed that the Erythrina crista-galli tolerated flooding by initially investing energy into the formation of morphoanatomical structures to maintain oxygen diffusion and ATP production. The effect of flooding on the leaves was reflected in increased energy dissipation through chlorophyll a fluorescence, likely as a mechanism to protect the photosynthetic apparatus.

Responses to excess iron in sweet potato: impacts on growth, enzyme activities, mineral concentration, and anatomy

86%

Adamski J. M., Danieloski R., Deuner S., Braga E. J., de Castro L. A., Peters J. A.

Acta Physiologiae Plantarum

2012

tom 34

nr 5

This study aimed to evaluate the effects of different iron concentrations on growth characteristics, antioxidant enzyme activities, nutrient absorption, and anatomical changes in sweet potato (Ipomoea batatas L.). To accomplish this, seedlings from apical branches of plants that had already been established in the greenhouse were rooted in a hydroponic sponge and then transplanted into a hydroponic system intermittently for 2 weeks and irrigated with nutrient solutions containing iron (ferric-EDTA) at concentrations of 0.45, 0.9, 4.5, and 9.0 mmol L⁻¹. Height, leaf area, and total biomass were significantly reduced at iron concentrations of 4.5 and 9.0 mmol L⁻¹. The iron concentrations in the established leaves and those that developed after the solution supplementation increased significantly. The amounts of other nutrients were also affected, with manganese showing the most significant decrease. The activities of the antioxidant enzymes, superoxide dismutase, and ascorbate peroxidase increased in plants grown in the 9.0 mmol L⁻¹ iron solution. At this concentration, however, the stomatal densities were reduced on the abaxial surfaces of the leaves, although the stomatal diameters increased. The ultrastructures of the radical cells showed mitochondrial impairment at high iron concentrations; however, the chloroplast structures remained unaffected.

Ograniczanie wyników

2 Acta Physiologiae Plantarum

2 Peters J. A.

1 Adamski J. M.

1 Bacarin M. A.

1 Braga E. J.

1 Danieloski R.

1 Deuner S.

1 Fernando J. A.

1 Larre C. F.

1 Marini P.

1 de Castro L. A.

1 2013

1 2012

Wyniki wyszukiwania

Growth and chlorophyll a fluorescence in Erythrina crista-galli L. plants under flooding conditions

Responses to excess iron in sweet potato: impacts on growth, enzyme activities, mineral concentration, and anatomy