Restricted Phosphorus Fertilization Increases the Betacyanin Concentration and Red Foliage Coloration of Alternanthera

Abstract

<jats:p>Phosphorus (P) deficiency commonly results in the development of red-to-purple coloration in plant foliage, typically attributed to anthocyanins. Betacyanins are a red pigment found in some plant species that do not produce anthocyanins, including <jats:italic>Alternanthera</jats:italic> sp. This study was conducted to investigate the effects of P nutrition on the betacyanin concentration and subsequent foliar coloration of ‘Purple Prince’, ‘Brazilian Red Hots’, and ‘Little Ruby’ alternanthera (<jats:italic>Alternanthera brasiliana</jats:italic>). The purpose of this study was to determine whether P fertilization management could enhance the coloration and aesthetic appeal of alternanthera. Custom fertilizers provided P concentrations of 0, 2.5, 5, 10, and 20 mg·L<jats:sup>−1</jats:sup> P. One-half of the plants from each P concentration were restricted to 0 mg·L<jats:sup>−1</jats:sup> P 1 month after transplant to determine whether adequate size could be attained before withholding P. Differences in P response were observed among cultivars for hue, betacyanin content, and plant size. Concentrations ≤5 mg·L<jats:sup>−1</jats:sup> P resulted in plants that were more compact in terms of plant height and diameter, had deeper red foliage coloration, and greater foliar betacyanins compared with plants grown with greater P concentrations. Plants initially grown with 5 or 10 mg·L<jats:sup>−1</jats:sup> P attained marketable size before P restriction and developed more red pigmentation compared with plants grown with P for the remaining duration of the study. Regression analysis demonstrated height was maximized with 3 to 8 mg·L<jats:sup>−1</jats:sup> P, diameter with 4.1 to 8.4 mg·L<jats:sup>−1</jats:sup> P, and branching with 10.0 mg·L<jats:sup>−1</jats:sup> P. Foliar betacyanin concentrations were greatest in plants grown without P, reaching 269 mg/100 g fresh weight, whereas plants grown with 10 or 20 mg·L<jats:sup>−1</jats:sup> P were 95% less (averaged ≈13 mg/100 g fresh weight). This study demonstrates that P restriction can benefit the aesthetic appeal of alternanthera and provides the first confirmation that P nutrition is associated with betacyanin accumulation.</jats:p>

Microbial Inoculation Improves Growth, Nutritional and Physiological Aspects of Glycine max (L.) Merr.

“…Therefore, P is often a limiting nutrient in agricultural systems and its deficiency decreases agricultural productivity. Therefore, chemical fertilizers are widely used for optimal yields; however, they are expensive, cause eutrophication of rivers, and their use in tropical acidic soils is limited by their low ion exchange capacity [ 2 , 3 , 4 , 5 , 6 ]. Although P is abundant in many soil types, most of it is not readily accessible to plants due to the high affinity of phosphate anions for Fe, Al, and CaO resulting in the formation of less soluble compounds [ 7 ].…”

Spectroscopic Analyses Highlight Plant Biostimulant Effects of Baker’s Yeast Vinasse and Selenium on Cabbage through Foliar Fertilization

“…It is involved in the chemical energy storage and transfer as a macroergic bond—e.g., in adenosine triphosphate, high-energy bonds used for storing and transferring free energy in biological systems. Phosphorus deficiency is characterized by excess production of anthocyanins [ 62 ], leading also to the diminishing of plant growth [ 63 ], while excess phosphorus may lead to leaf necrosis [ 64 , 65 ].…”