These results suggest that on a slope, on clayey soils, root asymmetry appears to be a consequence of several environmental factors such as inclination, shallow-slides and soil compactness. In addition, this adaptive growth seems to counteract the turning moment induced by the self-loading forces acting in slope conditions, and as a consequence improves the tree stability.
Knowledge of belowground structures and processes is essential for understanding and predicting ecosystem functioning, and consequently in the development of adaptive strategies to safeguard production from trees and woody plants into the future. In the past, research has mainly been concentrated on growth models for the prediction of agronomic or forest production. Newly emerging scientific challenges, e.g. climate change and sustainable development, call for new integrated predictive methods where root systems development will become a key element for understanding global biological systems. The types of input data available from the various branches of woody root research, including biomass allocation, architecture, biomechanics, water and nutrient supply, are discussed with a view to the possibility of incorporating them into a more generic developmental model. We discuss here the main focus of root system modelling to date, including a description of simple allometric biomass models, and biomechanical stress models, and then build in complexity through static growth models towards architecture models. The next progressive and logical step in developing an inclusive developmental model that integrates these modelling approaches is discussed.
Lentil (Lens culinaris Medik.) is one of the most ancient crops of the Mediterranean region used for human nutrition; an extensive differentiation of L. culinaris over millennia has resulted in a number of different landraces. As a consequence of environmental and socio-economic issues, the disappearance of many of them occurred in more recent times. To investigate the potential of proteomics as a tool in phylogenetic studies, testing the possibility to identify specific markers of different plant landraces, 2-D gel electrophoretic maps of mature seeds were obtained from seven lentil populations belonging to a local ecotype (Capracotta) and five commercial varieties (Turca Rossa, Canadese, Castelluccio di Norcia, Rascino and Colfiorito). 2-DE analysis resolved hundreds of protein species in each lentil sample, among which only 122 were further identified by MALDI-TOF PMF and/or nanoLC-ESI-LIT-MS/MS, probably as a result of the poor information available on L. culinaris genome. A comparison of these maps revealed that 103 protein spots were differentially expressed within and between populations. The multivariate statistical analyses carried out on these variably expressed spots showed that 24 protein species were essential for population discrimination, thus determining their proposition as landrace markers. Besides providing the first reference map of mature lentil seeds, our data confirm previous studies based on morphological/genetic observations and further support the valuable use of proteomic techniques as phylogenetic tool in plant studies.
The effect of wind loading on seedlings of English oak (Quercus robur L.) was investigated. Instead of using a traditional wind tunnel, an innovative ventilation system was designed. This device was set up in the field and composed of a rotating arm supporting an electrical fan, which emitted an air current similar to that of wind loading. Oaks were sown from seed in a circle around the device. A block of control plants was situated nearby, and was not subjected to artificial wind loading. After 7 months, 16 plants from each treatment were excavated, and root architecture and morphological characteristics measured using a 3D digitiser. The resulting geometrical and topological data were then analysed using AMAPmod software. Results showed that total lateral root number and length in wind stressed plants were over two times greater than that in control trees. However, total lateral root volume did not differ significantly between treatments. In comparing lateral root characters between the two populations, it was found that mean root length, diameter and volume were similar between the two treatments. In trees subjected to wind loading, an accentuated asymmetry of root distribution and mean root length was found between the windward and leeward sides of the root system, with windward roots being significantly more numerous and longer than leeward roots. However, no differences were found when the two sectors perpendicular to the wind direction were compared. Mean tap root length was significantly higher in control samples compared to wind stressed plants, whilst mean diameter was greater in the latter. Wind loading appears to result in increased growth of lateral roots at the expense of the tap root. Development of the lateral root system may therefore ensure better anchorage of young trees subjected to wind loading under certain conditions.
Linker histone protein variants are expressed in different tissues, at various developmental stages or induced by specific environmental conditions in many plant species. In most cases, the function of these proteins remains unknown. In the work presented here an antisense strategy has been used to study the function of the drought-induced linker histone, H1-S of tomato. Three independent H1-S antisense tomato mutants, selected for their inability to accumulate H1-S in response to water stress, were studied. These mutants have been characterized at the physiological and morphological levels. Histone H1-S antisense transgenic plants developed normally indicating that H1-S does not play an important role in the basal functions of tomato development. No differences were detected in chromatin organization, excluding a structural role for H1-S in chromatin organization. However, differences between the wild-type and antisense plants were observed in leaf anatomy and physiological activities. This analysis indicates that H1-S has more than one function, at different times, in controlling plant water status, highlighting the complexity of the water stress response.
We investigated the effects of seasonal changes\ud in soil moisture on the morphological and growth traits\ud of fine roots (<2 mm in diameter) in a mature Turkeyoak\ud stand (Quercus cerris L.) in the Southern Apennines\ud of Italy. Root samples (diameter: <0.5, 0.5–1.0, 1.0–1.5,\ud and 1.5–2.0 mm) were collected with the Auger method.\ud Mean annual fine-root mass and length on site was\ud 443 g m!2 (oak fine roots 321 g m!2; other species\ud 122 g m!2) and 3.18 km m!2 (oak fine roots 1.14 km\ud m!2; other species 2.04 km m!2), respectively. Mean\ud specific root length was 8.3 m g!1. All fine-root traits\ud displayed a complex pattern that was significantly related\ud to season. In the four diameter classes, both fineroot\ud biomass and length peaked in summer when soil\ud water content was the lowest and air temperature the\ud highest of the season. Moreover, both fine-root biomass\ud and length were inversely related with soil moisture\ud (p < 0.001). The finest roots (<0.5 mm in diameter)\ud constituted an important fraction of total fine-root\ud length (79 %), but only 21 % of biomass. Only in this\ud root class, consequent to change in mean diameter,\ud specific root length peaked when soil water content was\ud lowest showing an inverse relationship (p < 0.001).\ud Furthermore, fine-root production and turnover decreased\ud with increasing root diameter. These results\ud suggest that changes in root length per unit mass, and\ud pulses in root growth to exploit transient periods of low\ud soil water content may enable trees to increase nutrient\ud and water uptake under seasonal drought conditions
Mechanical stress is a widespread condition caused by numerous environmental factors that severely affect plant stability. In response to mechanical stress, plants have evolved complex response pathways able to detect mechanical perturbations and inducing a suite of modifications in order to improve anchorage. The response of woody roots to mechanical stresses has been studied mainly at the morphological and biomechanical level, whereas investigations on the factors triggering these important alterations are still at the initial stage. Populus has been widely used to study the response of stem to different mechanical stresses and, since it has the first forest tree genome to be decoded, represents a model woody plant for addressing questions on the mechanisms controlling adaptation of woody roots to changing environments. In this study, a morphological and physiological analysis was used to investigate factors controlling modifications in Populus nigra woody taproots subjected to mechanical stress. An experimental model analyzing spatial and temporal mechanical force distribution along the woody taproot axis enabled us to compare the events occurring in its above-, centraland below-bending sectors. Different morphogenetic responses and local variations of lignin and plant hormones content have been observed, and a relation with the distribution of the mechanical forces along the stressed woody taproots is hypothesized. We investigated the differences of the response to mechanical stress induction during the time; in this regard, we present data referring to the effect of mechanical stress on plant transition from its condition of winter dormancy to that of full vegetative activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.