Plant Origin, but Not Phylogeny, Drive Species Ecophysiological Response to Projected Climate.

Knowledge of the relationship between environmental conditions and species traits is an important prerequisite for understanding determinants of community composition and predicting species response to novel climatic conditions. Despite increasing number of studies on this topic, our knowledge on importance of genetic differentiation, plasticity and their interactions along larger sets of species is still limited especially for traits related to plant ecophysiology. We studied variation in traits related to growth, leaf chemistry, contents of photosynthetic pigments and activity of antioxidative enzymes, stomata morphology and photosynthetic activity across eight species growing along altitudinal gradients in Himalayas cultivated in three different temperature regimes and explored effects of among species phylogenetic relationships on the results.

The disadvantages of being a hybrid during drought: A combined analysis of plant morphology, physiology and leaf proteome in maize.

A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response.

Cytokinin oxidase/dehydrogenase overexpression modifies antioxidant defense against heat, drought and their combination in Nicotiana tabacum plants.

Cytokinins (CKs) as well as the antioxidant enzyme system (AES) play important roles in plant stress responses. The expression and activity of antioxidant enzymes (AE) were determined in drought, heat and combination of both stresses, comparing the response of tobacco plants overexpressing the main cytokinin degrading enzyme, cytokinin oxidase/dehydrogenase, under the control of root-specific WRKY6 promoter (W6:CKX1 plants) or constitutive promoter (35S:CKX1 plants) and the corresponding wild-type (WT). Expression levels as well as activities of cytosolic ascorbate peroxidase, catalase 3, and cytosolic superoxide dismutase were low under optimal conditions and increased after heat and combined stress in all genotypes.

Nitrogen metabolism and gas exchange parameters associated with zinc stress in tobacco expressing an ipt gene for cytokinin synthesis.

Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The impact of zinc (tested levels Zn1=250, Zn2=500, Zn3=750mgkg(-1)soil) on gas exchange parameters (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration) and nitrogen utilization by plants resulted in changes of free amino acid concentrations (glutamic acid, glutamine, asparagine, aspartate, glycine, serine, cystein) and differed for transformed and non-transformed tobacco plants. For pot experiments, tobacco plants (Nicotiana tabacum L.

The long-term effect of zinc soil contamination on selected free amino acids playing an important role in plant adaptation to stress and senescence.

Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The objective of this study is to determine amino acid changes associated with elevated CK production in ipt transgenic tobacco (Nicotiana tabacum L., cv.

The physiology and proteomics of drought tolerance in maize: early stomatal closure as a cause of lower tolerance to short-term dehydration?

Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In our study, two maize (Zea mays L.) genotypes with contrasting sensitivity to dehydration were subjected to moderate drought conditions.

Nitric oxide, reactive nitrogen species and associated enzymes during plant senescence.

Leaf senescence is often associated with increased oxidative damage to cellular macromolecules by reactive oxygen species. However, very little is known about other radicals: gaseous free radical nitric oxide and related molecules--reactive nitrogen species. This review brings a short survey of the questions.

Antioxidant protection during ageing and senescence in chloroplasts of tobacco with modulated life span.

We studied changes in antioxidant protection during ageing and senescence in chloroplasts of tobacco (Nicotiana tabacum L., cv. Wisconsin) with introduced SAG(12) promoter fused with ipt gene for cytokinin synthesis (transgenic plants with increased levels of cytokinins, SAG) or without it (control).

Recovery of maize (Zea mays L.) inbreds and hybrids from chilling stress of various duration: photosynthesis and antioxidant enzymes.

The differences between two maize (Zea mays L.) inbred lines and their F1 hybrids in their response to chilling periods of various duration (1, 2, 3 or 4 weeks) and subsequent return to optimum temperatures were analysed by the measurement of the photosystem (PS) 1 and 2 activity, the photosynthetic pigments' content and the activity of antioxidant enzymes. The PS2 activity and the chlorophyll content decreased in plants subjected to 3 or 4 weeks of chilling, but not in those subjected to 1 or 2 weeks of chilling.