Flowers under pressure: ins and outs of turgor regulation in development

Abstract

BackgroundTurgor pressure is an essential feature of plants; however, whereas its physiological importance is unequivocally recognized, its relevance to development is often reduced to a role in cell elongation.ScopeThis review surveys the roles of turgor in development, the molecular mechanisms of turgor regulation and the methods used to measure turgor and related quantities, while also covering the basic concepts associated with water potential and water flow in plants. Three key processes in flower development are then considered more specifically: flower opening, anther dehiscence and pollen tube growth.ConclusionsMany molecular determinants of turgor and its regulation have been characterized, while a number of methods are now available to quantify water potential, turgor and hydraulic conductivity. Data on flower opening, anther dehiscence and lateral root emergence suggest that turgor needs to be finely tuned during development, both spatially and temporally. It is anticipated that a combination of biological experiments and physical measurements will reinforce the existing data and reveal unexpected roles of turgor in development.

Endosperm turgor pressure decreases during early Arabidopsis seed development

“…To test whether the physical properties of the seed coat might vary during the developmental window studied, we carried out 1 µm indentations of seed coat cells with an atomic force microscope. Under these conditions, measurements are mostly influenced by cell turgor pressure (Beauzamy et al, 2014). We were unable to detect significant differences in stiffness of the outer cells of the testa between the globular and late heart stage of development (Fig.…”

“…During development, however, although turgor pressure drives plant growth, differential growth is generally thought to be achieved by regulated changes in cell wall extensibility, rather than by changes in cell turgor pressure (Beauzamy et al, 2014). A potential exception is the developing seed.…”

Measuring forces and stressesin situin living tissues

“…1Bb). Analyzing developmental changes in turgor pressure using AFM showed that these can be finely tuned to support flower opening, anther dehiscence and lateral root emergence (Beauzamy et al, 2014).…”

Growing Out of Stress: The Role of Cell- and Organ-Scale Growth Control in Plant Water-Stress Responses

“…The growth rate of a root drops immediately after transfer to hyper-osmotic media largely due to the escape of water from the cell and the reduction in turgor pressure (Shabala and Lew, 2002;Geng et al, 2013). Interestingly, while turgor pressure can be restored rapidly through an increase in the concentration of osmolytes in the cell, a process termed osmotic adjustment (Beauzamy et al, 2014), growth rate generally recovers at a much slower pace. Depending on the strength of the applied stress, cells in the elongation zone may enter a quiescent stage before their growth rate is recovered (Geng et al, 2013).…”