Effeot of Moisture Stress on Submicrosoopic Struoture of Maize Roots

Abstract

The effect of dehydration on root behaviour and its submicroscopic structure was studied. Root segments were dehydrated above sodium chloride solutions of various concentrations and the degree of dehydration was expressed as percentage loss of weight. Loss of more than 70% of initial weight proved lethal. On loss of 60-70% some of the roots preserved their ability to resume growth on rehydration.

Structural and Functional Aspects of Transport in Roots

“…Ic). Parallel complexes of ER induced by water stress (Ciamporova, 1976;Nir et al , 1969) also disintegrate rapidly. Fragmentation of the long ER elements and dilation of the fragments (Figs.…”

“…Electron microscopic investigation has shown that ultrastructure damage brought about by mild water stress is reversible (Bergtrom, 1982;Crevecoeur et al, 1976;Marinos and Fife, 1972;Nir et al, 1969;Noailles, 1978). The maintenance of cell membrane continuity of the individual cell compartments has been considered to be crucial for the capacity to repair ultrastructure (Fellows and Boyer, 1978).…”

“…Ultrastructural changes within maize root cells caused by non-lethal water stress recover within 45 min to 4 hrs (Nir et al, 1969). During rehydration of water-stressed embryos of wheat (Marinos and Fife, 1972) and maize (Crevecoeur et a/., 1976) all the cell components recovered their structure.…”

Differences in drought tolerance between cultivars of field bean and field pea. A comparison of drought-resistant and drought-sensitive cultivars

“…This effect, however, depends, both on the genetically determined variation of the morphological features and on physiological adaptation of plants to water stress. The final effect of drought on plant growth and yield crop is the resultant of the operation of many factors: besides anatomical and morphological adaptation, a marked role is played by physiological and metabolic adaptation responsible for the ability of the cells and tissues for structural and functional regeneration of cytoplasmatic membranes and cellular organella in the case of the occurrence of transient, reversible physiological injuries (Nir et al 1969, Poljakoff-Mayber, 1981, Ciamparowa 1989, Peterson 1989, Grzesiak et al 1997.…”

“…Genotypic responses of crop plants to water stress were also reflected in a number of root morphological and anatomical traits (Nir et al 1969, PoljakowMayber 1981, Galamay et al 1992). These study also revealed a sizeable variation in root morphology between field bean and field pea cultivars (Grzesiak et al 1997).…”