The apoplast and its significance for plant mineral nutrition

Abstract

SummaryIt has only recently become apparent that the apoplast plays a major role in a diverse range of processes, including intercellular signalling, plant-microbe interactions and both water and nutrient transport. Broadly defined, the apoplast constitutes all compartments beyond the plasmalemma -the interfibrillar and intermicellar space of the cell walls, and the xylem, including its gas-and water-filled intercellular space -extending to the rhizoplane and cuticle of the outer plant surface. The physicochemical properties of cell walls influence plant mineral nutrition, as nutrients do not simply pass through the apoplast to the plasmalemma but can also be adsorbed or fixed to cell-wall components. Here, current progress in understanding the significance of the apoplast in plant mineral nutrition is reviewed. The contribution of the root apoplast to short-distance transport and nutrient uptakes is examined particularly in relation to Na + toxicity and Al 3+ tolerance. The review extends to long-distance transport and the role of the apoplast as a habitat for microorganisms. In the leaf, the apoplast might have benefits over the vacuole as a site for short-term nutrient storage and solute exchange with the atmosphere.

Studying guard cells in the intact plant: modulation of stomatal movement by apoplastic factors

“…Apoplastic Ca 2+ concentrations in this range were also recently listed in a review by Sattelmacher (2001). These Ca 2+ concentrations are strikingly close to the concentration that gives a maximal light-induced stomatal opening in V. faba (MacRobbie, 1987) and Arabidopsis thaliana (Roelfsema & Prins, 1995).…”

Silicon induced Fe deficiency affects Fe, Mn, Cu and Zn distribution in rice (Oryza sativa L.) growth in calcareous conditions

“…2). These elements were localized mainly in the outer layers, probably in 414 the cell walls of the epidermis which contain negatively charged sites that bind metal 415 15 ions (Sattelmacher, 2001). Also, these elements may be retained by the iron plaque due 416 to adsorption or co-precipitation mechanisms (Liu and Zhu, 2005 (Fig.…”

Efecto del zinc sobre la inducción de ramas productivas en gulupa (Passiflora edulis Sims)

“…El zinc puede también ser liberado extracelularmente al apoplasto de la estela en regiones donde la banda de Caspary no está completamente formada (White, 2001). Los flujos apoplásticos son dominados por la capacidad de intercambio catiónico de la pared celular, la formación de la banda de Caspary y los flujos hídricos (Sattelmacher, 2001). …”