Figure 1.
ABA accumulation and expression analysis of the OsABA8ox genes.
(A) Expression patterns of OsABA8ox genes in different tissues of rice. (B) ABA accumulation and (C) OsABA8ox genes expression in rice leaves during PEG-mimic dehydration treatment and rehydration. Four-leaf stage seedlings were treated with 20% PEG for 4 h, and then transferred to nutrient solution for rehydration. Error bars are standard deviations based on three replicates.
Figure 2.
Stress tolerance assays of wild type plants and the transgenic rice.
(A) Relative expressions of OsABA8ox3 gene in RNAi and overexpression lines; (B) Performance of WT control and OsABA8ox3 RNAi-9, RNAi -27 and overexpression lines after 7 d soil drought stress and 4 d recovery. (C) Survival rate of rice seedlings after drought stress and rewatering. Error bars are standard deviations based on three replicates (n > 40). ** Indicates significant difference from wild-type at P = 0.01.
Figure 3.
Physiological changes in the OsABA8ox3-RNAi and -overexpression transgenic plants.
(A) ABA contents, (B) MDA contents and (C) antioxidant enzyme activities in the WT and OsABA8ox3-RNAi and -overexpression transgenic seedlings under normal condition and PEG treatment. Four-leaf stage seedlings were treated with 20% PEG for 2 h, then the samples were quickly frozen with liquid nitrogen. Error bars are standard deviations based on three replicates. ** Indicates significant difference from wild-type at P = 0.01.
Figure 4.
Relative expression levels of 9 stress-related genes in the WT and OsABA8ox3 RNAi transgenic plants under normal and PEG-treated conditions detected by qRT-PCR.
Four-leaf stage seedlings were treated with 20% PEG for 2 h, and then the samples were quickly frozen with liquid nitrogen for RNA extraction. The genes include dehydration-responsive element-binding protein (Os06g03670), zinc finger protein (Os05g10670), late embryogenesis abundant proteins (Os05g46480, Os01g50910 and Os04g49980), dehydrin family proteins (Os11g26760 and Os01g50700) and heat shock protein (Os03g16920 and Os02g54140).
Figure 5.
ABA sensitivity of the OsABA8ox3 transgenic seeds during germination and post-germination growth.
(A) Seed germination, (B) Post-germination root growth and (C) Root length of WT and OsABA8ox3-RNAi and -overexpression transgenic plants in response to exogenous ABA. Seeds treated with water and ABA (1μM and 5μM) were imbibed at 28°C to facilitate germination and post-germination growth. Error bars are standard deviations based on three replicates. ** Indicates significant difference from wild-type at P = 0.01.