Modeling available 2,4-dichlorophenoxyacetic acid in a tissue culture medium containing activated carbon

Abstract

Clonal propagation of high-value forest trees by somatic embryogenesis can help meet industry needs for uniform and high quality raw materials. Low embryogenic tissue initiation frequencies for loblolly pine (Pinus taeda L.) pose a limitation in work towards commercialization of this technology. At the time our research began most work on somatic embryo culture initiation in loblolly pine reported success in the range of 1-5%. Activated carbon (AC) has been reported to improve many tissue culture systems including embryogenic tissue initiation in Douglas-fir. To improve initiation frequencies in loblolly pine, the development of an AC-containing system was explored. In order to better understand the availability of 2,4-dichlorophenoxyacetic acid (2,4-D D ) in initiation medium, we tracked media surface concentrations of free or available 2,4-D D . Media containing 1/2 modified P6 salts, 1.5% maltose, 2% myo-inositol, case amino acids, glutamine, vitamins, and 0.4% Gelrite were modified to include 0.625 -2.5 g l )1 of activated carbon (Sigma C-9157, acid washed) and 110 -440 mg l )1 2,4-D D . Adsorption and availability of 2,4-D D in AC-containing medium was tracked by C 14 labeled 2,4-D D present in surface moisture absorbed into filter paper. High correlations were found between -available 2,4-D D and time when AC and initial 2,4-D D concentrations were held constant, -available 2,4-D D and AC concentration when initial added 2,4-D D and time were held constant, and -available 2,4-D D and initial 2,4-D D when AC and time were held constant. All of these relationships were exponential, not linear. Multiple regression models inputting initial 2,4-D D added to medium in mg l À1 , activated carbon added to medium in %, and time in days, were able to explain 85-88% of the variability in available 2,4-D D . These models can be used to achieve target levels of available 2,4-D D by adjustment of initial 2,4-D D levels or AC content.

Effect of Light and Activated Charcoal on Tracheary Element Differentiation in Callus Cultures of Pinus Radiata D. Don

“…A further increase of the concentration of activated charcoal did not increase the rate of TE differentiation, because the estimated means of TE differentiation on TIM 10 and TIM 20 were very similar to that of TIM 5 with 39.93 and 39.43%, respectively. It has been shown earlier that activated charcoal absorbs hormones such as 2,4-D or phenolic substances from the medium and plant cells (Pan and van Staden, 1998;von Aderkas et al, 2002;Toering and Pullman, 2005). We have found that TE differentiation in callus grown in light is inhibited on TIM 0 medium containing 4.5 lM 2,4-D (data not shown).…”

Optimization of germination, callus induction, and cell suspension culture of African locust beans Parkia biglobosa (Jacq.) Benth

“…On the other hand, (charcoal + 50 mg/l citric acid) treatment produced the minimum values 25, 1.06 and 0.11 for callus production, fresh and dry weight, respectively and browning color developing in callus cell culture was observed in this treatment. This result describes the effect the plant hormone 2, 4-D plus active charcoal [61], [62]. However, there was higher browning on callus cell culture in MS medium devoid antioxidant or charcoal, all the callus which produced with citric or ascorbic acid or without were brown in color and turn black after 3–4 weeks.…”

Establishment and optimization of cell growth in suspension culture of Papaver bracteatum: a biotechnology approach for thebaine production

“…The explants cultured on plant growth regulator-free MS medium and MS medium containing 3 g/L activated charcoal did not produce calli (Table 1). This may be due to the adsorption of plant growth regulators (2,4-D and kinetin) in medium by activated charcoal (Pan and Van Staden, 1998;Toering and Pullman, 2005;Van Winkle and Pullman, 2005). The percentage of callus induction in MS medium supplemented with 1 mg/L 2,4-D, 0.1 mg/L kinetin, and with or without ascorbic acid was not significantly different.…”