Root Osmotic Adjustment under Osmotic Stress in Maize Seedlings 1. Transient Change of Growth and Water Relations in Roots in Response to Osmotic Stress

Genotypic Variations in Responses of Lateral Root Development to Transient Moisture Stresses in Rice Cultivars

“…On the other hand, drought was induced using polyethylene glycol 6000 (PEG 6000) (4%, W/V) to attain -0.13MPa water potential. PEG has been reported to have no apparent toxic effects under wellaerated condition (Verslues et al, 1998;Raymond and Smirnoff, 2002;Ober and Sharp, 2003;Ogawa et al, 2005Ogawa et al, , 2006aOgawa et al, , 2006b) and hence, can mimic the drying effects of soil environment. Seven days after the onset of the moisture stress treatments, the seedlings of each genotype were transferred to their contrasting moisture stress treatments for another 7 days.…”

Root Osmotic Adjustment under Osmotic Stress in Maize Seedlings. 2. Mode of Accumulation of Several Solutes for Osmotic Adjustment in the Root

“…We found that mild water stress, such as −0.13 MPa treatment, affected solute accumulation and water relations (Ogawa and Yamauchi, 2006) in maize seminal root, as compared with the control (−0.08 MPa). Büssis and Heineke (1998) also showed that the amino acid concentration of young leaf of Solanum tuberosum was increased by osmotic stress induced by adding 10% (w/v) polyethyleneglycol 6000 (approximately −0.2MPa) to external hydroponics solution.…”

“…The sum of the concentrations of potassium, reducing sugars and total amino acids differs from the total solute concentrations calculated from the osmotic potential (Ogawa and Yamauchi, 2006). The difference at minute 20 was 0.5 mM, 28, 124, and 176 mM in the control, −0.13 MPa, −0.41 MPa and −0.89 MPa treatment groups, respectively.…”

“…White Pop) were germinated, transplanted onto nets fl oating on nutrient solution, and grown for 48 hours, as previously described (Ogawa and Yamauchi, 2006) and then transferred to PEG solutions for osmotic stress treatment. 0 (control), 50, 200 and 300 g of polyethylene glycol 6000 (PEG) (CaHC Co., Ltd, Japan) per liter was dissolved in the nutrient solution to induce osmotic stress.…”

“…For analysis of solutes, the segments of the second leaf at 10 mm from the tip (leaf mature zone) (Michelena and Boyer, 1982) and seminal roots at 0 −6 mm from the tip (root elongating zone) and 14− 20 mm from the tip (root elongated zone) (Ogawa and Yamauchi, 2006) were excised. At the sampling, the third leaf was just emerging.…”