Differences in photosynthetic characterization of salt tolerance for two rice (Oryza sativa) cultivars

Abstract

We photosynthetically characterized two rice cultivars -salt-sensitive ~Annapurna', and salt-tolerant 'Don~in' -growing under NaCI stress. Both cultivars showed an increase in Fo/Fm (the ratio of initial to maximal chlorophyll fluorescence) and a decrease in Fv/Fm (an indicator of the photochemical efficiency of PS II). In particular, the Fv value for Annapurna significant declined while FJFm was enhanced when plants were exposed to salt stress for 4 d. Annapurna also exhibited more rapid decreases in the coefficients for photochemical quenching (qQ) and non-photochemical quenching (qNP) than did Dongjln. In contrast, zeaxanthin formation was largely influenced by exposure to light rather than to high salinity, with Annapurna having a higher rate of production compared with Dongjin. When both cultivars were exposed to salt stress for 2 d, Annapurna had a much lower rate of photosynthetic oxygen evolution, corresponding to only 46% of the control; the rate for Dongjin was 90% of the control. Salt stress in both cultivars induced the accumulation of two osmoprotectants, glycinebetaine and proline, the rate being higher for the latter. These results indicate that Annapurna is more sensitive than Dongjin to salt stress, in terms of its deterioration in photosynthetic function.

Transcription factor OsHsfC1b regulates salt tolerance and development in Oryza sativa ssp. japonica

“…Cultivars differing in stress tolerance exhibit contrasting expression profiles, as demonstrated for salt and drought stress, where increasing sensitivity is positively correlated with an increasing number of differentially expressed stress-related genes ( Walia et al 2005 ; Degenkolbe et al 2009 ). Among japonica cultivars, Dongjin is considered to be more salt tolerant than Nipponbare ( Oh et al 2003 ; Ferdose et al 2009 ) and we observed a greater reduction of root FW and DW of empty-vector control plants in the Nipponbare background as compared with Dongjin wild-type plants under salt stress (Fig. 4 C), fitting the observed expression of stress marker genes.…”

Compatible Solute Engineering in Plants for Abiotic Stress Tolerance - Role of Glycine Betaine

“…The exogenous application of GB and Cho in the culture media would provide an alternative way for improving the defense mechanisms of plants to salt stress [64]. Rice has been reported as being a GB non-accumulator, while GB has been detected in small amounts in rice cultivars exposed to salt stress, including KDML105 [65], Homjan [66], and Annapurna and Dongjin [67]…”

PPIase activities and interaction partners of FK506‐binding proteins in the wheat thylakoid

“…As chaperones for specific membrane proteins, lumenal immunophilins have been linked to thylakoid membrane assembly during chloroplast biogenesis in cereals (Blomqvist et al 2008, Gollan and Bhave 2010a), and may also be important for acclimation mechanisms involving reorganization of membrane complexes, such as state transitions and cyclic electron flow (CEF), which maintain balanced ATP and NADPH production under fluctuating environmental conditions (Allen 2002). State transitions and CEF are also coping mechanisms for plants in stress conditions and are implicated in temperature and salt tolerance in cereals and other crops (Clarke and Johnson 2001, Lu et al 2008, Oh et al 2003, Wise et al 2004), presenting the immunophilins in the cereal thylakoid as clear candidates to study the fine‐tuning of cereal photosynthesis in response to environmental conditions. This work investigated three thylakoid‐localized FKBPs in wheat, and is the first functional characterization of lumenal immunophilins from a cereal plant.…”