Morphological plasticity of spring and winter wheats in response to changing temperatures

Abstract

Temperature change induces morpho-physiological responses, whose significance for plant function under this modified environmental condition is mostly unclear. Plastic responses to temperature changes from optimal (25°C) to chilling (5°C) conditions or vice versa, as compared with constant temperature treatments, were studied in spring and winter wheat. Plants grown at 5°C had smaller leaves, less stomata and larger root systems than their counterparts grown at 25°C. Plants at 5°C therefore had larger effective root : shoot ratio, defined as the ratio between total area of roots and stomata. Spring and winter cultivars differed in root growth, leaf growth and stomatal frequency following a shift in temperature. Nevertheless, both cultivar types reached similar effective root : shoot ratios, which were typical for each temperature. We also found changes in leaf thickness, transverse vascular bundle area and xylem : phloem ratios. Shifting temperature triggered rapid changes in leaf and root carbohydrate content and osmotic potential. Our results suggest that temperature-induced plasticity may play a role in ameliorating possible water deficits caused by large soil–air temperature differentials in natural environments.

Effect of Gibberellin and Ethephon on Growth and Yield of Bread Wheat Grown in Different Sowing Dates

“…The number of tiller related to the environmental and genetics factors, because the dynamic of potential tillering ability for cultivar depends on the suitability of environmental factors [16]. Temperature plays important role among the environmental factors which affects tillering phenomenon, prevailing temperature during initiation, growth and development of leaf primordial and its expansion that reflected in the increase leaf node of the stem [17] [18]. The suitable climatic factors such as temperature, light and relative humidity (data not shown) for producing of tillers were exist during this stage in D 3 sowing which extended from beginning of full third leaf to the begin of elongation (ZGS13 -ZGS31) which reflected in the hasting emergency, leaf and expansion and perhaps its number.…”

Anatomical and chemical characteristics of foliar vascular bundles in four reed ecotypes adapted to different habitats

“…It has been the subject of numerous studies, because it may also constrain the distribution of resources within a plant (Orians and Jones, 2001;Orians et al, 2002;Zwieniecki et al, 2003). Multiple characteristics of vascular structures have been investigated, such as modifications to the wall architecture, ion composition, protein expression, and alteration of the xylem/ phloem ratio, all of which are thought to be involved in the resistance of the plant to environmental stresses (Child et al, 2003;Equiza and Tognetti, 2002;Saijo et al, 2001;Zwieniecki et al, 2003). Wang et al (1997) found that salinity influenced the patterns of lignification, peroxidase activity, and extension deposition in the cortex and vascular tissues in Atriplex prostrata Boucher and the changes in cell wall composition occurred at different salinities.…”

“…The cell wall consists of a complex matrix of carbohydrate polymers, proteins, phenolic compounds, and other components, which determine the plasticity of the walls through cross-links and/or interactions (Brownlee, 2002;Enstone et al, 2003;Equiza and Tognetti, 2002;Kaczkowski, 2003;Marga et al, 2003).…”

Temperature Impact on the Forage Quality of Two Wheat Cultivars with Contrasting Capacity to Accumulate Sugars

“…Two wheat (Triticum aestivum L.) cultivars were selected for their contrasting morpho-physiological responses to low temperature, which have been described elsewhere [29,32,33]. Briefly, ProINTA Pincén is a winter hardy wheat that reduces its growth more and accumulates higher sugar concentration than Buck Patacón under low temperatures.…”

“…The concentration of soluble protein and sugars in wheat leaves may vary, depending on genotypic and environmental conditions [25][26][27][28]. Exposure of grasses to low temperature induces a steady accumulation of both components, while reversion to non-chilling conditions determines a very rapid decline in their concentration [25,29]. Considerable variation in the capacity to accumulate sugars and proteins exists among wheat cultivars: cultivars which undergo deeper cold-acclimation (winter hardy cultivars) are able to accumulate substantially higher amounts of compatible solutes in their cells compared with less hardy cultivars [26][27][28].…”