Exogenous Cytokinin Promotes Epipremnum aureum L. Growth through Enhanced Dry Weight Assimilation rather than through Changes in Partitioning

Abstract

Aims: Benzylaminopurine (BAP) sprays have been shown to increase leaf size and leaf appearance rate, as well as biomass accumulation in pot-grown Epipremnum aureum L. BAP-mediated enhanced growth could either be the consequence of a higher investment of dry weight in leaf area development thus leading to a positive dry weight accumulation feedback, to a promoting effect on dry weight assimilation per unit leaf area. Study Design: A randomized complete block factorial design with three blocks was used. Original Research ArticleDi AJEA, 5(5): 419-434, 2015; Article no.AJEA.2015 Results: A single 5mg L -1 BAP application was enough to increase the dry weight accumulation rate in comparison to untreated controls, irrespective of the light intensity. A strong direct relationship between the relative growth rate (RGR) and the net assimilation rate (NAR) were found, while an inverse relationship was observed between RGR and the leaf area ratio (LAR). Even though BAP increased dry weight partitioning to the aerial part, as revealed by shoot vs. root allometric analysis, this did not result in a LAR increase, but rather in higher stem dry weight accumulation, in association with a decrease in the leaf area partitioning coefficient (LAP). NAR promotion by BAP was associated with an increased N content per unit leaf area, rather than with changes in chlorophyll content. Conclusion: Our results on the ornamental shade plant E. aureum also provide information which may help to increase productivity to this crop from a grower perspective.

Biomass Accumulation in the Fern Asplenium nidus avis (L) under Root Restriction

“…These last results indicated higher frond thickness and a proportional higher photo assimilate partition to leaves as pot volume increased. The strong correlation between most growth parameters related to frond area expansion and frond anatomical structure and RGR were similar to those found for other ornamental vascular plants [15,16,17,18].…”

Cytokinin-Regulated Physiological Parameters Affected by an Exogenous Dopamine Spray in Brussels Sprout (Brassica oleracea var. gemmifera)

“…Because the environmental conditions (daily temperatures and photon flux radiation) in the three experiments were quite different, we can hypothesize that endogenous cytokinin synthesis can change in response to environmental variables such as temperature and photon flux radiation. In agreement with this assumption, several studies have found a positive interaction between cytokinins and photosynthetic active radiation [9,10,29] or temperature [30,31]. We may also speculate that some of the dopamine-inhibited physiological processes had different endogenous cytokinin thresholds, which define the final response of plants.…”

“…To understand these results, it must be kept in mind that the primary shoot apical meristem is responsible for generating all above ground organs and is controlled by hormones, which regulate biosynthesis and transport of other hormones, and by hormone interactions. These hormones include auxins, cytokinins and gibberellins, which act both independently and in combination to regulate meristem function [9,10,14,18]. Leaves are formed into an initial group of cells within the meristem; one of the earliest markers for leaf initiation is the downregulation of the KNOTTED and WUSCHEL genes in these cells [19].…”

“…Our previous studies on Epipremnum aureum, for example, have suggested that an exogenous cytokinin or auxin spray would affect its photosynthetic active radiation (PAR). The application of cytokinin can also affect the plastochron length, leaf size, photosynthetic rate, leaf mesophyll anatomy and photo assimilate partitioning [8,9,10]. In contrast, little is known about the effects of an exogenous dopamine spray and data on Brussels sprout (Brassica oleracea var.…”

Combined effects of NPK fertilizer with foliar application of benzyladenine or gibberellic acid on Dracaena marginata ‘Bicolor’ grown in different potting media

“…The favorable effect of GA 3 on the plant growth may be attributed to its effect on stimulating the expression of enzymes involved in cell wall loosening and genes controlling cell division and also stimulating microtubule rearrangements associated with cell expansion (Satish and Manju, 2018). It was stated that the increase of plant growth by BA mainly associated with higher net assimilation rates and increased N content per unit leaf area (Di Benedetto and Galmarini, 2015), while increasing plant growth due to GA 3 may be attributed to its influence on increasing photosynthesis rate through increasing leaf surface (Lima et al, 2014). Moreover, increasing plant growth as a result of combined growth hormones with nutrient may be owing to physiological role of hormones and nutrient in synthesis of the plant phytochemicals through the action of various enzymes activity and protein synthesis (Tandel et al, 2018).…”