Anatomical Features of the Cell Wall Ingrowth in the Cortical Cells outside the Endodermis and the Development of the Casparian Strip in Loquat Trees

Formation of Endodermis-like Cells with Casparian Strip and Thick Wall Cells Derived from Pericycle in the Roots of Feijoa sellowiana (Myrtaceae)

“…In the present study, thick wall cells occurred in a different area from phi thickening in Rosaceae trees (Nii et al, 2004;Pan et al, 2006) and crescent thickening in red bayberry (Song et al, 2011b). The appearance of the thick wall cells observed in this study was similar to that of the crescent-shaped thickening reported in red bayberry roots (Song et al, 2011b).…”

“…The development of suberin lamellae and Casparian strips in the endodermis, root lignification, and thickening of the cortical cell wall associated with root maturation are particularly important in perennial tree roots. Suberin lamella deposition and Casparian strip formation in the endodermis and exodermis (a layer of hypodermal cells adjacent to the epidermis) have been studied extensively in the roots of many plant species, particularly fruit trees, such as pear (Esau, 1943), apple (Mackenzie, 1979;Riedhart and Guard, 1957), loquat (Nii et al, 2004;Pan et al, 2006), grapevine (Song et al, 2011a), and red bayberry (Song et al, 2011b). The Casparian strip has been shown to block the free apoplast movement of water, ions, heavy metals, and fluorescent dyes (Bücking et al, 2002;Nagahashi et al, 1974;Peterson et al, 1981;Robards and Robb, 1972).…”

“…The Casparian strip has been shown to block the free apoplast movement of water, ions, heavy metals, and fluorescent dyes (Bücking et al, 2002;Nagahashi et al, 1974;Peterson et al, 1981;Robards and Robb, 1972). Nii et al (2004) and Pan et al (2006) reappraised cell wall growth (phi thickening) in the cortical cells of loquat (Rosaceae) tree roots. These authors found that phi thickening occurred before suberin lamella formation in the Casparian strip of loquat roots.…”

Anatomical Development of Phi Thickening and the Casparian Strip in Loquat Roots

“…While many reports have been published on phi thickening, generally in Rosaceae fruit trees (Esau, 1943;Mackenzie, 1979;Nii et al, 2004;Pan and Nii, 2005;Peterson et al, 1981;Riedhart and Guard, 1957), relatively little has been published on the relationship between phi thickening and the development of the Casparian strip in relation to aging of the root and environmental conditions, although the differentiation and development of the Casparian strip has been reported for several species of fruit trees (Esau, 1943;Mackenzie, 1979;Riedhart and Guard, 1957;Weerdenburg and Peterson, 1983). Particularly, the relationship between the Casparian strip and phi thickening in relation to root development and aging should be investigated in order to understand the defense mechanism against drought stress in Rosaceae trees.…”

“…Knowledge of anatomical changes in the roots should contribute to our understanding of drought tolerance in Rosaceae trees. Recently, Nii et al (2004) and Pan and Nii (2005) reappraised cell wall ingrowth (phi thickening) in the cortical cells and Casparian strip of Rosaceae fruit roots. As a result, the extent of phi thickening was pronounced in loquat (Eriobotrya), moderate in apple (Malus) and pear (Pyrus), and slight in peach (Prunus).…”