Modifications to Thylakoid Composition during Development of Maize Leaves at Low Growth Temperatures

Abstract

The effects of reductions in growth temperature on the development of thylakoids of maize (Zea mays var LG11) leaves are examined. Thylakoids isolated from mesophyll cells of leaves grown at 170 and 140C, compared with 250C, exhibited a decreased accumulation of many polypeptides, which was accompanied by a loss of activity of photosystems (PS) I and I. Probing the polypeptide profiles with a range of antibodies specific for thylakoid proteins demonstrated that a number of polypeptides encoded by the chloroplast genome failed to accumulate at low temperatures. Although thylakoid protein synthesis was reduced severely at 140C compared with 250C, major synthesis of both chloroplast and nuclear encoded polypeptides was detected. It is suggested that the lack of accumulation of some thylakoid proteins at low temperatures may be due to an inability to stabilize the proteins in the membranes. A number of thylakoid polypeptides were found to appear as the growth temperature was decreased. Analyses of pigments and polypeptides demonstrated that decreases in the photosystem reaction center core complexes occur relative to the light harvesting complex associated with PS II at reduced growth temperatures. Differential effects on the development of PSI and PSII were also observed, with PSII activity being preferentially reduced. Reductions in PSII content and activity occurred in parallel with decreases in the quantum yield and light-saturated rate of CO2 assimilation. Fractionation of thylakoid pigment-protein complexes showed that the ratio of monomeric:oligomeric form of the light harvesting complex associated with PSII increased at low growth temperature, which is consistent with a chill-induced modification of thylakoid organization. Many, but not all, of the characteristic changes in thylakoid protein metabolism, which were observed when leaves were grown at low temperatures in controlled environments, were identified in leaves of a field maize crop during the early growing season when low temperatures were experienced by the crop. Chill-induced perturbations of thylakoid development can occur in the field in temperate regions and may have implications for the photosynthetic productivity of the crop.

The effect of low growth temperature on Hill reaction and Photosystem 1 activities in three biotypes of Kochia scoparia (L.) Schrad. with different sensitivity to atrazine and ALS-inhibiting herbicides

“…This agrees with the results of other experiments made on cold-stressed plants, where the increased efficiency of electron transport around PS1 complex was observed (Sonoike 1998, Pessarakli 1999. PS1 is probably less susceptible to low temperature-induced damage compared to PS2, particularly under low-light conditions when no photodamage to this complex should occur (Nie and Baker 1991, Körnerová and Holá 1999, Sonoike 1998, Pessarakli 1999. All three biotypes examined responded to the cultivation at 10°C by an increase of the PS1 activity; this increase was slightly higher in the atrazine-sensitive biotypes Jihlava and Karlín than in the resistant biotype Bubny (Figure 4).…”

Photosynthetic performance of two maize genotypes as affected by chilling stress

“…After three weeks of chilling treatment chilled plants had fewer leaves and internodes in comparison with non-chilled ones (Table 1, Figure 1A, B). Decrease in growth rate, but no effects on plant ontogeny, were observed by Nie and Baker (1991), Nie et al (1992), Sowinski et al (2003). Sowinski et al (2003) also found thicker leaf blades in chilled maize plants.…”

“…Low spring temperatures can seriously damage growth and ontogeny of young maize plants due to the inhibition of their photosynthesis (Nie and Baker 1991, Nie et al 1992, Dolstra et al 1994, Massacci et al 1995. Maize as a biological species includes a large number of genotypes which differ in their tolerance to low temperatures (chilling or cold) (Dolstra et al 1994, Massacci et al 1995.…”

The relationship of antioxidant enzymes and some physiological parameters in maize during chilling

“…Nie and Baker (1991) reported that although re-exposure to the optimal temperatures caused a rapid synthesis and accumulation of pigments and many proteins to levels close to those found in the leaves grown at 25°C, the leaves do not attain similar levels of photosynthetic competence. It is possible that the exposure to low temperature during early stages of leaf development restricts the synthesis of components essential for the thylakoid development, which cannot be made at later stages of leaf development when the temperature increases.…”

“…It is known that chilling in the light sensitize photosynthesis to photoinhibition (Xu et al 1999), which results in bleaching of photosynthetic pigments (Nie and Baker 1991). A decrease in the chlorophyll content was suggested to reduce the absorption of potentially damaging light and therefore the risk of singlet oxygen formation is relatively lower (Leipner et al 2000).…”