Functional dynamics of plant growth and photosynthesis – from steady‐state to dynamics – from homogeneity to heterogeneity

Abstract

Plants are much more dynamic than we usually expect them to be. This dynamic behaviour is of paramount importance for their performance under natural conditions, when resources are distributed heterogeneously in space and time. However, plants are not only the cue ball of their physical and chemical environment. Endogenous rhythms and networks controlling photosynthesis and growth buffer plant processes from external fluctuations. This review highlights recent evidence of the importance of dynamic temporal and spatial organization of photosynthesis and of growth in leaves and roots. These central processes for plant performance differ strongly in their dependence on environmental impact and endogenous properties, respectively. Growth involves a wealth of processes ranging from the supply of resources from external and internal sources to the growth processes themselves. In contrast, photosynthesis can only take place when light and CO 2 are present and thus clearly requires 'input from the environment'. Nevertheless, growth and photosynthesis are connected to each other via mechanisms that are still not fully understood. Recent advances in imaging technology have provided new insights into the dynamics of plant-environment interactions. Such processes do not only play a crucial role in understanding stress response of plants under extreme environmental conditions. Dynamics of plants under modest growth conditions rise from endogenous mechanisms as well as exogenous impact too. It is thus an important task for future research to identify how dynamic external conditions interact with plant-internal signalling networks to optimize plant behaviour in real time and to understand how plants have adapted to characteristic spatial and temporal properties of the resources from their environment, on which they depend on.

Starch as a major integrator in the regulation of plant growth

“…One striking example is the daily alternation between a positive C balance in the light and a negative C balance in the dark. Growth nevertheless continues at night (5). This continued growth is possible because some newly fixed C accumulates as starch in the light and is remobilized at night to support respiration and growth.…”

La susceptibilidad de las bromeliáceas epífitas al cambio climático

“…De manera que ante cualquier leve variación en el ambiente, tanto el proceso fotosintético como el crecimiento de las plantas cambian (Schurr et al, 2006). Lo anterior muestra que las epífi tas tienen rangos de tolerancia estrechos a cambios en el ambiente; por lo que, la mayor diversidad y abundancia de especies epífi tas se encuentran en los bosques húmedos, como los encinares y el mesófi lo de montaña (Espejo-Serna et al, 2007), debido a la distribución uniforme de la lluvia durante el año (Benzing, 1998).…”

Remote Sensing of Photosynthetic Parameters

“…LUE refers to the projected ground surface and describes the net canopy CO 2 fixation. The spatial variability of LUE results in enormous variations of net photosynthetic productivity (NPP), which ranges from 30 to 1000 g C m -2 in different ecosystems (Schurr et al, 2006). Thus knowledge of the spatial distribution of LUE, fAPAR or chlorophyll is essential for a realistic estimation of photosynthetic processes.…”

“…Plant water absorption features affect the reflectance behaviour in the SWIR leading to a strongly decreased reflectance at high plant water contents. Light reaction is commonly measured using the chlorophyll absorption features in the VIS, which are known to correspond well with the fraction of absorbed photosynthetically active radiation (fAPAR) (Schurr et al, 2006). At the canopy level, the efficiency of carbon fixation is denoted.…”