Osmotic adjustment in indoor grown cassava in response to water stress

Abstract

Ike, 1-F-and Thurtell, G-W-1981. Osmotic adjustment in indoor grown cas,sava in response to water stress--Physiol. The water content-water potential relation in stressed and unstressed cassava {Manihot species) was examined to ascertain (i) the magnitude of osmotic adjustment in response to water stress and (ii) the mechanisms of such adjustments-Water stress resulted in a displacement of the water content-potential relation such that at any leaf water potential the water content was higher in the stressed plants-The osmotic potentials of turgid leaves (100% relative water content) were -0-97 and -1.00 MPa in the unstressed cultivars CMC 9 and MCOL 113 respectively. In the stressed plants, the values were-1-13 MPa (CMC 9) and-1-14 MPa (MCOL 113)-The 0-14 to 0-16 MPa osmotic potential difference between the stressed and unstressed plants suggests that a stress-induced osmotic adjustment occurred in both cuhivars-The bulk volumetric elastic moduli at turgor pressures above 0-10 MPa were 9.84 MPa (CMC 9) and 13-58 MPa (MCOL 113) in the unstressed plants-Tbe higher values found in the stressed plants, 14-56 MPa in CMC 9 and 16-91 MPa in MCOL 113, suggest a stress-induced decrease in cell wall elasticity-Hence, the observed shift in the water content-potential relations in the cassava involved both an osmotic adjustment and a decrease in cell wall elasticity-Increasing the number of stress cycles per plant did not eause a further displacement of the water content-potential curves-

Bulk elastic moduli and solute potentials in leaves of freshwater, coastal and marine hydrophytes. Are marine plants more rigid?

“…While a few marine plants have relatively flexible cell walls, most studies indicate that plants residing in saline environments will have rigid tissues ( Ike and Thurtell 1981 ; Melkonian et al 1982 ; Bolaños and Longstreth 1984 ). The results from this study, with the aforementioned exceptions, support this previously untested assertion.…”

Sweetpotato Responses to Mid‐ and Late‐Season Soil Moisture Deficits

“…2). (Siddique et al, 2000), cassava (Manihot utilisima Pohl) (Ike and Thurtell, 1981), and cotton (Gossypium hirsutum L.) (Lokhande and Reddy, 2014). They further reported that the midday LWP in sweetpotato plants grown in open-top chambers under well-watered and water-stressed conditions for 14 d had LWPs of -0.75 and -1.5 MPa, respectively.…”

“…Interrelationships between plant processes and LWP and soil moisture deficit have been well documented for other crop species such as wheat (Triticum spp.) (Siddique et al, 2000), cassava (Manihot utilisima Pohl) (Ike and Thurtell, 1981), and cotton (Gossypium hirsutum L.) (Lokhande and Reddy, 2014).…”

Response of Cassava Leaf Area Expansion to Water Deficit: Cell Proliferation, Cell Expansion and Delayed Development

“…In response to mild drought, cassava reduces transpiration substantially by closing its stomata, as do other species that act to retain water during drought episodes (El Sharkawy et al, 1984;Tardieu and Simonneau, 1998;Alves and Setter, 2000). In contrast, the extent of other drought responses, such as osmotic adjustment and accumulation of dehydrin proteins, is small (Ike and Thurtell, 1981;Alves and Setter, 2004). This is similar to the behaviour of many highly productive species, such as cowpea (Vigna unguiculata) and maize (Zea mays), when they are grown in environments with short-term episodic droughts (Itani et al, 1992;Serraj and Sinclair, 2002).…”