【硫代谢与干旱胁迫】Kai Xun Chan Markus Wirtz Su Yin Phua Gonzalo M. Estavillo Barry J. Pogson. Balancing metabolites in drought: the sulfur assimilation conundrum. Trends in Plant Science 2012 18(1): 18-29.
Abstract
A key plant response to drought is the accumulation of specific sets of metabolites that act as osmoprotectants osmolytes antioxidants and-or stress signals. An emerging question is: how do plants regulate metabolism to balance the ‘competing interests’ between metabolites during stress? Recent research connects primary sulfur metabolism (e.g. sulfate transport in the vasculature its assimilation in leaves and the recycling of sulfur-containing compounds) with the drought stress response. In this review we highlight key steps in sulfur metabolism that play significant roles in drought stress signaling and responses. We propose that a complex balancing act is required to coordinate primary and secondary sulfur metabolism during the drought stress response in plants.
【根际模式】Susanne Schwinning. Do we need new rhizosphere models for rock-dominated landscapes?Plant and Soil
Abstract
Background
In this issue Estrada-Medina and coworkers described the diversity of materials in the rhizosphere of the Yucatán karst México and quantified the distribution of roots across karst features.
Scope
This commentary explores the implications of their work for below-ground competition and the dynamics of plant-available water on seasonal to inter-annual timescales. Though details differ seasonal dynamics of water use were consistent with a two-layer model characterized by water uptake from shallow soil and rock layers during the wet season and deeper soil pockets and rock layers during the dry season. Soil pockets were more densely rooted than rock and experienced large fluctuations in soil moisture suggesting intense below-ground competition. Total water storage capacity in the rhizosphere was far greater than actual storage in the year of the study. This raises the question whether some storage components in the karst rhizosphere fluctuate on time scales exceeding 1 year.
Conclusions
Despite the significant global extent of karst and their larger than proportional contribution to global biodiversity vegetation models have ignored their unique rhizosphere structure. Differences in water storage could affect the responses of karst ecosystems and communities to climate change.
【土壤-植物-微生物系统】Olivier Husson. Redox potential (Eh) and pH as drivers of soil-plant-microorganism systems: