The role of meta-topolins on the photosynthetic pigment profiles and foliar structures of micropropagated 'Williams' bananas

0382874 - ÚEB 2013 RIV PT eng J - Journal Article
Aremu, A.O. - Bairu, M. W. - Szüčová, Lucie - Finnie, J.F. - van Staden, J.
The role of meta-topolins on the photosynthetic pigment profiles and foliar structures of micropropagated 'Williams' bananas.
Journal of Plant Physiology. Roč. 169, č. 15 (2012), s. 1530-1541. ISSN 0176-1617. E-ISSN 1618-1328
R&D Projects: GA MZe QI92A247
Grant - others:GA MŠk(CZ) ED0007/01/01
Program: ED
Institutional research plan: CEZ:AV0Z50380511
Keywords : carotenoids * chlorophylls * cytokinins
Subject RIV: GK - Forestry
Impact factor: 2.699, year: 2012

The effect of five topolins (meta-Topolin= mT; meta-Topolin riboside = mTR; meta-Methoxy topolin = MemT; meta-Methoxy topolin riboside = MemTR and 6-(meta-methoxy)-9-(tetrahydropyran-2-yl)-topolin = MemTTHP) on the photosynthetic pigments and leaf structures of micropropagated 'Williams' bananas was compared with the commonly used benzyladenine (BA). Surface-decontaminated explants were cultured for 70 d on modified Murashige and Skoog (MS) basal medium and supplemented with 10, 20 or 30 mu M cytokinins (CKs). At 10 d intervals, the photosynthetic pigments were quantified via spectrophotometric methods for 7 cycles. Generally, the maximum pigment content was attained between 40 and 50 d. The control plantlets had the highest pigment content (1150 mu g/g FW). Among the CKs, 10 mu M MemTTHP generally had the best pigment stimulatory effect at the same period. After 40 d, scanning electron microscopy (SEM) of the foliar surface showed that the stomata density was highest in 10 mu M MemTTHP-treated and lowest in 10 mu M MemTR-treated plantlets. The stomatal structure and pore area also varied with the type and concentration of CK added. Generally, prolonging culture duration as well as increasing CK concentrations reduced the pigment content. However, the drastic breakdown in chlorophyll pigments beyond 50 d was slightly inhibited by the presence of mT, mTR, MemTTHP and BA compared to the control. The CK-treated plantlets at equimolar concentration had comparable chlorophyll a/b and total chlorophyll/carotenoid ratios after 10 d; probably as an adaptive measure. At the end of the current study, 10 mu M mT and mTR plantlets remained green as reflected by the higher total chlorophyll/carotenoid ratio as well as by the visual observations. A well-developed photosynthetic apparatus enhances the survival of in vitro plantlets during the acclimatization stage.
Permanent Link: http://hdl.handle.net/11104/0212980