Effects of Chemical Growth Retardants on Growth and Development of Sweetpotato (Ipomoea batatas (L.) Lam.) in Vitro

Abstract

Plant growth retardants were evaluated for their ability to reduce the growth rate of sweetpotato (Ipomoea batatas (L.) Lam.) in vitro. Nodal sections of cv. Jewel were cultured for 30 days on medium containing NDA, ancymidol, phosfon, TIBA, difenzoquat, chlormequat, ACC, mepiquat chloride, or daminozide at 0, 10 −4 , 10 −5 , 10 −6 , 10 −7 , or 10 −8 M. Difenzoquat, NDA, phosfon, and TIBA, at 10 −4 M, were lethal to axillary bud explants. A low concentration (10 −8 M) of chlorflurenol or NDA stimulated shoot elongation. The effective concentration range for most growth retardants was 10 −5 to 10 −6 M. Small (2-to 4-mm diameter) storage root-like swellings were observed on roots in cultures containing TIBA or ancymidol. The growth-inhibiting effects of ancymidol and NDA were transitory and did not persist through a 180-day culture period. Shoots cultured on medium containing 10 −5 M phosfon, TIBA, or difenzoquat were significantly shorter than control plants after a 180-day culture period. Culture on medium containing TIBA, NDA, ancymidol, or ACC resulted in abnormal leaf and stem development. Plants derived from nodal explants cultured on medium containing either phosfon or chlormequat were near normal in appearance but with some plants exhibiting interveinal chlorosis and reduced root system development.

The effect of sodium amidotrizoate on the growth and content of various metabolites in the green alga Chlorella vulgaris Beijerinck

“…This is in agreement with another finding. It is speculated that TIBA and other plant growth retardants act by inhibiting cell division in the subapical zones of the shoot apex and furthermore reduce stem elongation (Jarret 1997). In the light of these facts and our findings it could be supposed that sodium amidotrizoate also inhibits cell division.…”

“…Moreover, it is known that TIBA reduces phosphoenolopyruvate carboxylase (PEPC) and malate dehydrogenase (MDH) activity (Gilbert et al 2000). It was also documented that TIBA in concentrations ranging from 10 -8 -10 -7 M cause increasing accumulations of emergency sugars in the root system (Jarret 1997). The slight decrease of monosaccharides content was observed also in the algal cells grown in the medium containing sodium amidotrizoate.…”

“…Moreover, TIBA also suppressed the content of capsule wall chlorophyll in Aussie Gold plants, whereas it had no influence on the level of this parameter in UCR82 -6NS plants (Day 2000). On the other hand, it was reported that TIBA enhanced chlorophyll synthesis in plant stems and leaf tissues (Jarret 1997). Research concerning the Rosa hybrida L. indicated that the content of leaf chlorophyll a+b in 2-4 μM TIBA treated plants was higher by 6-55% than that of the control.…”

“…TIBA at a concentration of 10 -7 M had no effect on the stem height and shoot fresh weight. On the other hand, TIBA at a concentration of 10 -8 M caused a significant increase in sweet potato (Ipomoea batatas L.) stem growth (by 21%) and fresh weight of shoot (by 17%) (Jarret 1997). The examination concerning a few species of algae showed that TIBA had a significant influence on their growth and acted in a concentration-dependent manner.…”

Is phosphatidylglycerol essential for terrestrial life?

“…Plants adapted to low temperatures possess a very different isoform profile of PG to those adapted for warmer climes [88]. The PG isolates from sweet potato (optimum growth temperature ∼20-25°C [89,90]) undergoes the phase transition from gel to fluid lamellar (melts) at about 40°C (5 mM Mg ++ ) where that from spinach (optimum growth temperature ∼5°C [91]) melts at 20°C [88]. This is the result of an inversion in the FAR profile amongst PG isoforms.…”