Time course analysis of ABA and non-ionic osmotic stress-induced changes in water status, chlorophyll fluorescence and osmotic adjustment in Arabidopsis thaliana wild-type (Columbia) and ABA-deficient mutant (aba2)

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• 作者：Ceyda Ozfidan ^{ceyda.ozfidan@gmail.com} ; Ismail Turkan ; ^{ismail.turkan@ege.edu.tr} ; Askim Hediye Sekmen ^{hediye.sekmen@ege.edu.tr} ; Burcu Seckin ^{burcu_sec@hotmail.com}
• 关键词：Abscisic acid ; Arabidopsis thaliana ABA-deficient mutant (aba2) ; Chlorophyll fluorescence ; Drought stress ; Proline ; Water status
• 刊名：Environmental and Experimental Botany
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：86
• 期：Complete
• 页码：44-51
• 全文大小：837 K

文摘

In the present study, we investigated time course changes of water status including relative water content (RWC), leaf osmotic potential (¦·_¦°), stomatal conductance (g_s), proline (Pro), chlorophyll fluorescence (F_v/F_m) and total chlorophyll content in the Arabidopsis thaliana under PEG-induced drought stress after exogenous ABA treatment. To a better explanation for the role of ABA in the water status of A. thaliana to drought stress, wild-type (Columbia) and ABA-deficient mutant (aba2) of A. thaliana were used in the present study. Moreover, three weeks old Arabidopsis seedlings were applied exogenously with 50 ¦ÌM ABA and exposed to drought stress induced by 40 % PEG8000 (?0.73 MPa) for 6 h, 12 h and 24 h (hours). Our findings indicate that RWC of wild-type and aba2 started to decrease in the first 12 h and 6 h of PEG-induced drought stress, respectively. However, exogenous treatment of 50 ¦ÌM ABA increased their RWC under drought stress. On the other hand, while ¦·_¦° of both genotypes started to decrease in the first 6 h of drought stress, these declines in ¦·_¦° were prevented by ABA treatment under stress throughout the experiment; it was more pronounced in aba2 at 24 h. While the highest increase in g_s was obtained in aba2 after 24 h stress, ABA-induced highest decrease in g_s was obtained in the same genotype during 12 h, as compared to PEG-treated group alone. On the other hand, Pro content increased in all treatment groups of ABA-deficient mutant aba2 at 12 h and 24 h. However, Pro content in ABA + PEG treated aba2 plants was higher than in PEG- and ABA-treated plants alone at the end of the 24 h. Drought stress decreased F_v/F_m and total chlorophyll contents of both genotypes while 50 ¦ÌM ABA alleviated these reductions during drought stress, as compared to PEG stressed plants. On the other hand, 50 ¦ÌM ABA treatment alone did not create any remarkable effect on F_v/F_m and total chlorophyll contents.

These findings indicate that exogenous ABA showed an alleviative effect against damage of drought stress on relative water content, osmotic potential, stomatal conductance, proline, chlorophyll fluorescence and total chlorophyll content of both genotypes during 24 h of drought stress treatment.