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Os03g0230300, a rice homologue of SRO, termed as OsSRO1c, responds to multiple abiotic stresses[1][2].

Annotated Information


  • OsSRO1c was identified as a direct target gene of SNAC1 (stress-responsive NAC 1) involved in the regulation of stomatal aperture and oxidative response. SNAC1 could bind to the promoter of OsSRO1c and activate the expression of OsSRO1c[1]. OsSRO1c, a rice SRO gene which functions downstream of the stress-responsive transcription factor SNAC1, is the major stress-responsive gene in the rice SRO family[2].
  • OsSRO1c interacted with various stress-related regulatory and functional proteins, and some of the OsSRO1c-interacting proteins are predicted to be involved in the control of stomatal aperture and oxidative stress tolerance, which suggesting that OsSRO1c has dual roles in drought and oxidative stress tolerance of rice by promoting stomatal closure and H2O2 accumulation through a novel pathway involving regulators SNAC1 and DST[1].
  • Also, OsSRO1c is also involved in osmotic stress tolerance in rice[1]. OsSRO1c is involved in low temperature stress tolerance[2].

GO assignment(s): GO:0003950,GO:0005634, GO:0006471


  • The loss-of-function mutant of OsSRO1c showed increased stomatal aperture and sensitivity to drought, and faster water loss compared with the wild-type plant[1].
  • The ossro1c-1 mutant showed resistance not only to chloroplastic oxidative stress, but also to apoplastic oxidative stress. However, the ossro1c-1 mutant and artificial micro RNA OsSRO1c transgenic rice were significantly impaired in cold tolerance[2].
  • ossro1c-1 is also impaired in tolerance to low temperature. The low temperature sensitivity phenotype of ossro1c-1 was further confirmed by using the artificial microRNA of OsSRO1c (amiR-OsSRO1c) rice plants. The results showed that amiR-OsSRO1c lines were also hypersensitive to low temperature' stress[2].


  • OsSRO1c was induced in guard cells by drought stress, the expression of OsSRO1c is mainly regulated by SNAC1. OsSRO1c overexpression led to decreased stomatal aperture and reduced water loss. OsSRO1c-overexpressing rice showed increased sensitivity to oxidative stress. Expression of DST, a reported zinc finger gene negatively regulating H2O2-induced stomatal closure, and the activity of H2O2-scavenging related enzymes were significantly suppressed, and H2O2 in guard cells was accumulated in the overexpression lines[1].
  • OsSRO1c was strongly induced by drought, salt, cold, and heat treatments and slightly induced by UV, wounding, H2O2, and ABA treatment, which indicating that expression of OsSRO1c is responsive to multiple stresses[1]. Under cold and wound treatment, OsSRO1c was up-regulated. OsSRO1c was induced under UV treatment. Under the submergence treatment, OsSRO1c and OsSRO1e were down-regulated, which suggest that OsSRO1c may have a unique role in terms of stress responsiveness[2].
  • Expression of OsSRO1c was also analysed by qPCR in 16 organs/tissues. The results indicated that OsSRO1c had relatively high expression in calli, collar, stem, internodes, sheath, flag leaf, secondary branches of the panicle, and the spikelet hull[1].
  • The GFP signal was observed in root, auricle, stem, internodes, and vascular bundle of the leaf sheath, and the spikelet hull under normal growth conditions, which is consistent with the qPCR analysis of OsSRO1c expression in 16 organs/tissues[1].
  • OsSRO1c overexpression has a negative role in resistance to oxidative stress, which may be associated with the suppression of ROS-scavenging enzyme genes and the activity of ROS-scavenging enzymes[1].
  • Based on the expression profiling data, OsSRO1b had a relatively higher expression level than the other rice SRO genes. According to the cluster analysis, OsSRO1d and OsSRO1e had similar expression profiles, showing constitutive expression in various organs/tissues. OsSRO1a and OsSRO1c exhibited tissue and organ-specific expression patterns[2].
  • OsSRO1c exhibited very low expression in the embryo at the early grain development and ripening stages. However, high expression of OsSRO1c was detected in the ovary at the early grain developmental stage and endosperm at the ripening stage[2].


Fluorescence was observed only in the nucleus, which suggest that OsSRO1c is a nuclear protein[1].


Figure 1. Phylogenetic tree of SRO proteins in Arabidopsis and rice.(from reference [1]).
Figure 2. Phylogenetic analysis of the plant SRO protein family.(from reference [2]).
  • OsSRO1c belongs to the plant-specific SRO family. Phylogenetic tree analysis showed that OsSRO1c and SRO2–SRO5 were in the same group. OsSRO1c has high sequence similarity to both the PARP and RST domains of Arabidopsis SRO proteins(Fig. 1)[1].
  • The SRO proteins can be classified into two groups (I and II)[2]:
    • Group I can be further classified into three subgroups (Ia, Ib, and Ic).
      • RCD1 and SRO1 from A. thaliana along with SROs from all of the selected species excluding P. patens and spikemoss, formed the subgroup Ia.
      • The subgroup Ib contains only SROs from grass species including rice and B. distachyon.
      • SRO homologs from the bryophyte P. patens and the basal vascular plants S. moellendorffii, together with the homologs from castor bean, cassava, cotton, flooded gum, poplar, rice, and B. distachyon, formed the subgroup Ic.
    • Group II can be further classified into two subgroups (IIa and IIb).
      • SRO2 and SRO3 from A. thaliana along with their homologs in other species formed the subgroup IIa.
      • Subgroup IIb contains SRO4 and SRO5 from A. thaliana, and their homologs from 11 species.
    • All the group II SROs from flax belong to the subgroup IIa, while all group II SROs from flooded gum belong to subgroup IIb.

Knowledge Extension

  • The SROs (SIMILAR TO RCD-ONE) are a group of plant-specific proteins which have important functions in stress adaptation and development. They contain the catalytic core of the poly(ADP-ribose) polymerase (PARP) domain and a C-terminal RST (RCD-SRO-TAF4) domain. In addition to these domains, several, but not all, SROs contain an N-terminal WWE domain[3] .
  • The SRO protein family has six members in Arabidopsis. In the japonica rice genome, five members including OsSRO1c were annotated based on sequence analysis[3]
  • The SROs are a highly conserved family of plant specific proteins. Sequence analysis of the RST domain implicates a highly preserved protein structure in that region. This might have implications for functional conservation[3] .

Labs working on this gene

  • National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 You J, Zong W, Li X, et al. The SNAC1-targeted gene OsSRO1c modulates stomatal closure and oxidative stress tolerance by regulating hydrogen peroxide in rice[J]. Journal of experimental botany, 2013, 64(2): 569-583.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 You J, Zong W, Du H, et al. A special member of the rice SRO family, OsSRO1c, mediates responses to multiple abiotic stresses through interaction with various transcription factors[J]. Plant molecular biology, 2014, 84(6): 693-705.
  3. 3.0 3.1 3.2 Jaspers P, Overmyer K, Wrzaczek M, et al. The RST and PARP-like domain containing SRO protein family: analysis of protein structure, function and conservation in land plants[J]. BMC genomics, 2010, 11(1): 170.

Structured Information