Photosynthetic Parameters of Maize (Zea mays L.) Inbred Lines and F₁ Hybrids: Their Different Response to, and Recovery from Rapid or Gradual Onset of Low-temperature Stress

Abstract

The activity of photosystems (PS) 1 and 2, together with the content and ratio of photosynthetic pigments, were measured in three inbred lines and two F 1 hybrids of maize (Zea mays L.), grown in either optimum or low temperature (LT) conditions. The ability of chilling-stressed plants to deal with the negative effects of long-term exposure to LT and to recover the efficiency of photosynthetic apparatus after their return to optimum temperatures was examined during spring and autumn seasons. The aim was to analyse the possible differences between the rapid and gradual onset of LT on the response of young maize plants to chilling stress. The distinctive superiority of hybrids over their parental lines, found during the exposure of maize plants to LT, was not always retained after the return of chilling-stressed plants to optimum growth conditions. The response of individual genotypes to chilling stress, as well as their ability to recover the photosynthetic efficiency from the cold-induced damage, strongly depended also on the duration and the rapidity of the onset of LT.

Photosynthetic performance of two maize genotypes as affected by chilling stress

“…These results could explain the relatively high P N in chilled CE 704 plants under saturating irradiance in autumn experiments. Holá et al (2003) observed a similar effect of moderate chilling temperatures during autumn on chlorophyll a content and values of PSII activity in plants of the same genotypes grown under similar experimental conditions. It could be concluded that the chilling of CE 704 plants during spring did not affect the efficiency of the photosynthetic apparatus but decreased its capacity.…”

Effects of Low Temperature on Leaf Anatomy and Photosynthetic Performance in Different Genotypes of Wheat Following a Rice Crop

“…In industrial chicory, cold stress affect the activity of enzymes involved in CO2 fixation or the photosynthetic utilization of CO2 (Devacht et al, 2009). In corn under cold stress, the CO2 fixation rate was affected initially, and the activity of the photosynthetic electron transport chain in the thylakoidal membranes further reduced (Holá et al, 2003). Under low temperature stress, wheat stomates are partially closed, leading to blocked transport of CO2 to the chloroplasts, as well as a decrease in Ci and Pn.…”

The influence of low-temperature on the photochemical activity of chloroplasts and activity of antioxidant enzymes in maize leaves

“…Mesophyll chloroplasts were isolated from the leaf tissue using standard techniques after homogenisation of leaf sample (Holá et al 2003(Holá et al , 2007. Their photochemical activity was measured polarographically (Clark type oxygen electrode, Theta´90, Prague, the Czech Republic) as the increase (PS 2) or decrease (PS 1) of oxygen amount in the suspensions of isolated chloroplasts after their irradiation (170 W m -2 PAR) and addition of the necessary electron donors, acceptors and other cofactors (for more details see Holá et al 2003Holá et al , 2007.…”

“…Unfortunately, physiological, biochemical and particularly genetical mechanisms responsible for the greater tolerance to chilling displayed by some maize genotypes are still poorly understood. The differences in the response of inbred and hybrid genotypes to low temperature and the changes in genetic determination of the photosynthetic parameters under chilling conditions have been only rarely studied , Holá et al 2003, the influence of the parental genotype on the performance of the progeny regarding these characteristics has, to our knowledge, never been studied. No information exists in this area also in case of the activities of antioxidant enzymes.…”