RUI: Growth Equations for Sporiangiophores of Phycomyces: Transpiration

多年来，布氏藻霉孢子囊团的感觉系统一直是人们感兴趣的对象。孢子囊是一种大型的单细胞，可以检测到几种不同的环境刺激，并对这些环境刺激做出反应，无论是对称的还是非对称的伸长生长速度变化。因此，对感觉系统的详细了解的基础是对孢子囊的生长速率的调节的深入的定量了解。拟议研究的长期目标是为孢子囊发育的所有阶段建立孢子囊生长速率和水分传输速率的定量关系(生长方程)。以往的研究表明，孢子囊吸水量的85%可能来自蒸腾作用，因此蒸腾作用是一个必须包含在定量关系中的重要过程。该项目的近期目标是扩展生长方程以包括蒸腾作用，并研究蒸腾作用过程作为发展和环境条件的函数。所获得的结果可能对蒸腾过程、水分运输、植物细胞生长和生长调节、植物细胞发育和感觉转导提供新的见解。Ortega博士建议通过实验确定真菌Phycomyces巨型单细胞的生物物理和生化特性的大小和变化，以便为这些细胞的生长速度和行为建立一个定量的数学模型。这些大细胞检测并响应几种不同的环境刺激，如光，伸长生长速度的对称或不对称变化，因此被用作阐明感觉传导过程的模型系统。他将在这里确定蒸腾作用(水分保持或损失)对生长速度的影响，并将这些信息纳入他的数学模型。这一结果将对理解其他真菌和绿色植物的细胞壁生长和水分运输机制具有更广泛的意义。

The sensory system of the sporangiophores of Phycomyces blakesleeanus has been of interest for many years. The sporangiophores are large single cells that detect and respond to several different environmental stimuli with either a symmetric or an asymmetric change in elongational growth rate. Thus, fundamental to a detailed understanding of the sensory system is an in-depth quantitative understanding of the regulation of the sporangiophore's growth rate. The long-term objective of the proposed research is to establish quantitative relationships (Growth Equations) for sporangiophore growth rate and water transport rate, for all stages of sporangiophore development. Previously, it was demonstrated that the sporangiophore may transpire up to 85% of its water uptake, thus transpiration is an important process which must be included in the quantitative relationships. The immediate objective of this project is to extend the Growth Equations to include transpiration, and to study the transpiration process as a function of development and environmental conditions. The results obtained may provide new insight into the transpiration process, water transport, plant cell growth and growth regulation, plant cell development, and sensory transduction. %%% Dr. Ortega proposes to experimentally determine the magnitude of, and changes in, biophysical and biochemical properties of the giant single cells of the fungus Phycomyces in order to establish a quantitative mathematical model for the growth rate and behavior of these cells. These large cells detect and respond to several different environmental stimuli such as light, with either a symmetric or asymmetric change in elongational growth rate and have thus been used as a model system for elucidating the sensory transduction process. He here will determine the effects of transpiration (water retention or loss) on growth rates and incorporate this information into his mathematical models. The results will have a wider significance in understanding the mechanics of cell wall growth and water transport in other fungi and also in green plants.