Effects Of Abscisic Acid Application Research Articles

Application of abscisic acid prevents leaf senescence at decreased irradiance

Several lines of evidence suggest that plant hormone abscisic acid (ABA) and the activity of alternative respiratory pathway are somehow interrelated. In this paper, we tested how an application of ABA affects the alternative oxidase (AOX) pathway and leaf senescence in Arabidopsis thaliana (L.) Heynh. Different effects of ABA application on the AOX activity were observed under high irradiance (HI) and low irradiance (LI). The expression of AOX1D gene was stimulated, whereas the expression of senescence marker gene WRKY53 was decreased due to ABA treatment. We also noticed that changes of AOX genes AOX1A and AOX1D, as well as AOX regulatory gene ANAC017, were rather inversely correlated with irradiance-dependent changes in AOX activity. The expression of AOX1D and WRKY53 was diminished due to the application of H2O2 under LI. Our results are indicative that in some conditions an exogenous application of ABA may suppress leaf senescence. This action does not go via the induction of AOX activity, despite stimulation of AOX genes.

Effect of Abscisic Acid Application on Pod Formation and Yield of Soybean Plants

Effect of Abscisic Acid Application on Pod Formation and Yield of Soybean Plants

53 Effect of Abscisic acid Application on Germination of Rice Seeds

53 Effect of Abscisic acid Application on Germination of Rice Seeds

Effect of abscisic acid application on root isoflavonoid concentration and nodulation of wild-type and nodulation-mutant soybean plants

Isoflavonoids (daidzein, genistein, and coumestrol) are involved in induction of nod genes in Bradyrhizobium japonicum and may be involved in nodule development as well. Abscisic acid (ABA) may also impact nodulation since ABA is reportedly involved in isoflavonoid synthesis. The current study was conducted to evaluate whether ABA plays a role in differential nodulation of a hypernodulated soybean (Glycine max L. Merr.) mutant and the Williams parent. Exogenous ABA application resulted in a decrease in nodule number and weight in both lines. Isoflavonoid concentrations were also markedly decreased in response to ABA application in both inoculated and noninoculated soybean roots. The inoculation treatment itself resulted in a marked increase in isoflavonoid concentrations of NOD1-3, regardless of ABA levels, while only slight increases occurred in Williams. The nodule numbers of both soybean lines across several ABA concentration treatments were highly correlated with the concentration of all three isoflavonoids. However, differences in internal levels of ABA between lines were not detected when grown in the absence of external ABA additions. It is concluded that differential nodule expression between the wild type and the hypernodulated mutant is not likely due to differential ABA synthesis.

Relationship between Abscisic Acid (ABA) Content and Maturation of the Sweet Cherry.

The changes in abscisic acid (ABA) content, ethylene evolution, and anthocyanin and sugar contents of the 'Satohnishiki' cherry fruit (Prunus avium L.), and the effect of ABA application on its maturation and coloring were investigated.1. Among sugars in the fruit, glucose was the highest in content followed by fructose and sorbitol. The total sugar content increased greatly from 38 days after full bloom (DAFB), at which time a concomitant rise in anthocyanin accumulation was also noted.2. The ethylene evolution per gram fresh weight fell continuously from 17 through 31 DAFB. It increased slightly from 31 DAFB to 38 DAFB, after which it decreased again. In contrast, the ethylene evolution per fruit increased greatly from 31 DAFB.3. The endogenous ABA levels of the pulp and peel were relatively high on 17 DAFB, but fell to lower levels by 31 DAFB. The ABA content in the pulp increased dramatical- ly from 31 DAFB, while the level in the peel rose slightly from 31 DAFB and more rapidly after 38 DAFB.4. ABA application to the fruit on 36 DAFB enhanced the total sugar and anthocyanin contents of the fruit.It is thus suggested that the ABA content may be related to the fruit growth rate, maturation and coloring of sweet cherry.