Improvement of ex vitro transfer of tobacco plantlets by addition of abscisic acid to the last subculture

Abstract

Tobacco (Nicotiana tabacum L.) plantlets were grown on Murashige and Skoog medium in ventilated Magenta boxes and for the last subculture 10 μM ABA was added to the medium. After three weeks plantlets were transferred into pots with Perlite moistened with water and grown in controlled conditions (16-h photoperiod, day/night temperature 25/20 °C, air humidity about 45 %) either under low or high irradiance of 150 (LI) and 700 (HI) μmol m -2 s -1 , respectively. Content of endogenous ABA was 271.7 pmol g -1 (f.m.) in ABA treated plantlets, while in control plantlets it was only 53.3 pmol g -1 (f.m.). After ex vitro transfer, stomatal conductance and transpiration rate decreased considerably in comparison with in vitro grown plantlets and remained lower also 7 d after ex vitro transfer, especially in ABA-treated plants and so wilting of plants was practically eliminated. Net photosynthetic rate also decreased 1 d after ex vitro transfer but after 7 d it was mostly higher than that of in vitro grown plantlets. Water use efficiency significantly increased in ABA-treated plants. Chlorophyll a+b content did not change immediately after ex vitro transfer, nevertheless, after 7 d chlorophyll content was higher in ABA-treated plants. Pool of xanthophyll cycle pigments (XCP) and the degree of their deepoxidation (DEPS), which are connected with harmless dissipation of light energy, increased under high irradiance. Contents of XCP and ABA precursors (neoxanthin and violaxanthin) were lower in ABA-treated plants than in control plants indicating less stress in these plants. Most chlorophyll a fluorescence parameters did not change considerably after ex vitro transfer and so the photoinhibition was not observed even under HI. Slight increase in non-photochemical quenching under HI in ABA-treated plants suggested their better photoprotection. Thus application of ABA to the last subculture can improve acclimatization of in vitro grown plants to ex vitro conditions

Improvement ofex vitroacclimatization of mulberry plantlets by supplement of abscisic acid to the last subculture medium

“…Means ± SE, n = 20 cuticle deposition on cells, sudden dehydration and increase in ROS production (Batkova et al 2008). In vitro cultured plantlets are characterized by deficient functionality of stomata, which is gradually recovered during ex vitro acclimatization (Dias et al 2013a, b;Hazarika 2006;Pospisilova et al 2009b). However, ABA application strongly reduced water loss even when stomata did not function normally (Pospisilova et al 2007), which decreased water stress during acclimatization of Ulmus minor, indicating a faster and efficient improvement of the water control mechanisms.…”

“…Higher irradiance can also increase the harmful stress and restrict a plantlet growth, resulting in the photoinhibition or generation of reactive oxygen species (ROS). Therefore, the regulation of transpiration and stabilization of water status as well as adequate operation of photosynthetic mechanism are very important for plant survival and its further growth during an adaptation period to the new growing environment (Desjardins et al 2009;Pospisilova et al 2009b). which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.…”

Proline levels, oxidative metabolism and photosynthetic pigments during in vitro growth and acclimatization of Pitcairnia encholirioides L.B. Sm. (Bromeliaceae)

“…According to Gour et al (2007), the chlorophyll content is one of the most important parameters for evaluation of the plant hardening after acclimatization. Carotenoids are also important in this phase, since they are required to protect the photosynthetic apparatus against damages caused by excess of radiant energy and contribute to non-enzymatic antioxidant defense systems (Perl-Treves and Perl, 2002;Pospíšilová et al, 2009). The results found in this work, with lower pigment accumulation in plantlets cultured in hermetically sealed tubes, especially in culture medium containing NAA, reinforce the hypothesis that the hermetic sealing of the vials could be detrimental to the development of autotrophic plants, reducing the efficiency and protection of the photosynthetic apparatus.…”

“…These results are in agreement with those found by Kadleček et al (2001), with tobacco, and indicate that the effects of in vitro conditions on the pigment contents may vanish after acclimatization and thus, for P. encholirioides, the alterations found in vitro would have a slight influence on photosynthesis after acclimatization. According to Pospíšilová et al (2009), the chlorophyll contents could be higher or lower in acclimatized plants when compared with in vitro plantlets. The differences could be attributed to irradiation conditions, culture medium composition and in vitro CO 2 concentration.…”

The role of abscisic acid in plant tissue culture: a review of recent progress

“…ABA acts as an anti-transpirant during the acclimatization of tissue culture-raised plantlets and reduces the relative water loss of the leaves of micropropagated plantlets during transplantation even when non-functional stomata are present (Pospisilova et al 1999(Pospisilova et al , 2007. Pospisilova et al (2009) recently reported that the addition of ABA to the last subculture improved the survival rate of tobacco plantlets transferred to the natural environmental conditions. Acclimatization can also be improved by the positive effect of ABA on Chlorophyll a content and other photosynthetic parameters as well as on plant growth (Pospisilova et al 1999(Pospisilova et al , 2007.…”