Evaluation of a ninhydrin procedure for measuring membrane thermostability of wheat

Abstract

Membrane thermostability (MT) is used widely to measure high‐temperature tolerance of wheat (Triticum aestivum L.). However, the method, which measures conductivity of electrolytes released from injured cells, is affected by environmental factors for growing plants and is not effective on maturing plants. Amino acids exosmose like inorganic electrolytes from cells that are damaged by high temperature but, unlike electrolytes, typically occur only in living cells. These studies determined whether measuring leakage of amino acids effectively assessed high‐temperature injury to wheat in comparison with the conductivity method, and if it was suitable for evaluating maturing plants. Membrane thermostability was measured by conductivity and ninhydrin methods on seedlings and maturing plants grown under controlled conditions and on 12 genotypes at two field locations. Relative injury (RI) values from hardened seedlings differed significantly among 12 genotypes. Rankings of the genotypes were similar for both methods in seedlings (r = 0.94), and values of both methods were significantly correlated in maturing plants (r = 0.90). The RI values by the ninhydrin method but not the conductivity method differed significantly among the 12 genotypes and identified the top‐yielding cultivars at both field locations, but results of neither method correlated with grain yields. The results showed that the ninhydrin method measures high‐temperature injury of young plants as successfully as the conductivity method, but neither method is suitable for maturing plants.

10.1007/s11183-008-1007-2

“…The percentage of electrolyte leakage was calculated by using the formulae; MP (%) = ( C 1 / C 2 ) × 100 , where C 1 and C 2 are the electrolyte conductivities measured before and after boiling, respectively [11]. Briefly, a portion of fresh leaf material was weighed into a glass beaker containing reverse osmosis water.…”

Mitigating effects of paclobutrazol on flooding stress damage by shifting biochemical and antioxidant defense mechanisms in mungbean(Vigna radiata L.) at pre-flowering stage

“…Membrane stability index was determined in terms of percentage of electrolyte leakage (Cekic et al 2001) and lipid peroxidation level was measured in terms of malondialdehyde (MDA) content (Hodges et al 1999). Hydrogen peroxide estimation was done as per the protocol of Mukherjee and Choudhary (1983).…”

Cold-hardening during long-term acclimation in a freeze-tolerant woolly bear caterpillar, Pyrrharctia isabella

“…Calculation of the cholesterol levels was performed by dividing the OD value of an unknown sample with the OD value of the calibrator and then by multiplying by a factor of 4.6 (concentration of the calibrator in mg 100 ml -1 ). The free proline and total amino acids were measured with ninhydrin solution (0.70 mol l −1 NaH 2 PO 4 , 0.30 mol l −1 Na 2 HPO 4 , 0.03 mol l −1 ninhydrin and 0.02 mol l −1 fructose) according to Cekic and Paulsen (2001) and Rosen (1957). A 0.2 ml sample, 0.8 ml deionized water and 1.0 ml ninhydrin solution were mixed in a Pyrex tube and heated in boiling water for 10 min.…”