Response of photosynthetic apparatus to moderate high temperature in contrasting wheat cultivars at different oxygen concentrations.
نویسندگان
چکیده
The photosynthetic responses to moderately high temperatures (38 degrees C, imposed at 21% or 2% O(2) in air and 1500 mumol m(-2) s(-1)) were compared in wheat (Triticum aestivum L.) cultivars grown in northern regions of Ukraine and expected to be relatively sensitive to high temperatures ('North' cultivars) and in cultivars grown in southern regions and expected to be relatively heat-tolerant ('South' cultivars). Heating intact leaves in 21% O(2) for 1 h decreased CO(2) assimilation by c. 63% in 'North' cultivars and only c. 32% in 'South' cultivars, with a decrease in PSII activity being observed in only one of the 'North' cultivars. Carboxylation efficiency was decreased by about 2.7-fold in 'North' cultivars with no significant effect in 'South' cultivars. The maximum rates of carboxylation by Rubisco in vivo, V(cmax), estimated from Farquhar's model, increased more than 2-fold in 'South' cultivars and remained unchanged in 'North' cultivars while the maximum rate of RuBP regeneration, J(max), decreased by 53% and 21% in 'North' and 'South' cultivars, respectively. Where the heat treatment was imposed in 2% O(2) this increased (as compared with treatment at 21% O(2)) the inhibitory effect on CO(2) assimilation in tolerant cultivars, but decreased it in sensitive ones. The results suggested that differences in tolerance of moderately high temperatures in wheat relate to the stability of the Rubisco function and to RuBP regeneration activity rather than to the effects on PSII activity or stomatal control.
منابع مشابه
Effects of Cadmium on Chemical Markers in Wheat (Triticum aestivum L.) Yield Production
A greenhouse experiment was conducted in 2013 in Research Lab of Karaj Islamic Azad University to determine the yield and activity of chemical markers as the response to different concentrations of Cadmium (Cd) (0, 5, 10 and 20 mg of Cd/kg of soil) in wheat cultivars (Karaj 1 and Karaj 2). Treatments were tested in a factorial experiment with four replications in 7.5 kg plastic pots. The respon...
متن کاملCatalase and Metallothionein genes expression analysis in wheat cultivars under drought stress condition
Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the hydrogen peroxide (H2O2) resulting reducing oxidative damage. In this research the gene expre...
متن کاملAssessment of Root Growth and Physiological Responses of Four Bread Wheat (Triticum aestivum L.) Cultivars to Salinity Stress
Enlarged root systems that extend into the salt affected soil improve water and nutrient capture by plants and can increase plant productivity. In order to examine root system characteristics of four bread wheat cultivars contrasting in salt tolerance (Arg, Ofoq, Tajan and Morvarid) a greenhouse experiment was conducted with applying two salinity levels (0 and 150 mM NaCl) on plants grown in PV...
متن کاملLow-Temperature Effects on Photosynthesis and Correlation with Freezing Tolerance in Spring and Winter Cultivars of Wheat and Rye.
Winter cultivars of rye (Secale cereale L., cv Musketeer) and wheat (Triticum aestivum L. cvs Kharkov and Monopol), but not a spring cultivar of wheat (Glenlea), grown at cold-hardening temperatures showed, at high irradiances, a higher proportion of oxidized to reduced primary, stable quinone receptor (QA) than did the same cultivars grown under nonhardening conditions. In addition, there was ...
متن کاملInfluence of Exogenously Applied Glycinebetaine on the Photosynthetic Capacity of Two Differently Adapted Wheat Cultivars under Salt Stress
Ameliorative effect of exogenously applied glycinebetaine (GB) on photosynthetic capacity of two wheat cultivars differing in salt tolerance grown under salt stress was assessed. Plants were grown under field conditions at 2.84, 15 dS/m in split-split plot design. Different levels of GB (no spray NS, 0.1% Tween 20 solution, 50 and 100 mM GB in 0.1% Tween 20 solution) were exogenously applied as...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of experimental botany
دوره 58 8 شماره
صفحات -
تاریخ انتشار 2007