Os06g0130100

From RiceWiki
Jump to: navigation, search

As a RLK gene, OsSIK1(Oryza sativa stress-induced protein kinase gene 1) is an Mn2+-dependent protein kinase and has the ability to autophosphorylate and phosphorylate other substrates in vitro[1].

Annotated Information

Function

  • OsSIK1 exhibits kinase activity in the presence of Mn2+, and the OsSIK1 kinase domain has the ability to autophosphorylate and phosphorylate myelin basic protein (MBP).
  • The OsSIK1 gene protects rice seedlings from salt and drought stresses by activating the antioxidative system. OsSIK1 appears to play a negative role in stomatal density: this may promote drought tolerance by diminishing water loss. It means OsSIK1 may suppress stomatal development in rice leaves. OsSIK1-mediated stress signaling may involve scavenging and detoxification of ROS.
  • The OsSIK1 genomic sequence contains 26 exons and 25 introns. The OsSIK1 cDNA encodes a protein of 980 amino acids. OsSIK1 is a typical RLK with multiple leucine-rich repeats[1].

GO assignment(s): GO:0004672, GO:0004674, GO:0005524, GO:0006468

Mutation

  • Three independent transgenic lines[1]:
    • OX-6-2
    • OX-7-1
    • OX-3-4
  • Three RNAi lines[1]:
    • RNAi-83-1
    • RNAi-13-1
    • RNAi-20-3
  • Mutant lines[1]:
    • sik1-1 (NE8025)
    • sik1-2 (NE1049)
  • RT-PCR analysis showed that OsSIK1 transcripts were absent in sik1-1 and sik1-2 plants(Figure 3h).
  • Transgenic rice plants with overexpression of OsSIK1 show higher tolerance to salt and drought stresses than control plants. On the

contrary, the knock-out mutants sik1-1 and sik1-2, as well as RNA interference (RNAi) plants, are sensitive to drought and salt stresses.

  • OsSIK1-RNAi plants only showed slight or mildly stressed phenotypes. The mutants had no OsSIK1 at all, whereas OsSIK1-RNAi plants still had a low level of OsSIK1 expression. Although OsSIK1-RNAi plants showed only mildly stressed phenotypes, these plants did not recover after the stress was removed. The injury to the SIK1-RNAi plants may have passed a certain critical point so that they could no longer recover. In contrast, OsSIK1-overexpressing plants recovered well after salt and drought stresses, suggesting that OsSIK1 evokes a mechanism in plants enabling them to both cope with the stress and then recover after the removal of the stress.
  • Two loss-of-function mutants, sik1-1 and sik1-2, and OsSIK1-RNAi plants all show higher stomatal density than control plants.

Expression

Figure 1. Expression of OsSIK1 in rice.(from reference [1]).
  • The expression of OsSIK1 was examined in rice seedlings in response to various abiotic stresses and treatments[1]:
    • Figure 1(a) shows that OsSIK1 was apparently induced under four treatments, including NaCl(200 mM), drought (PEG treatment), H2O2 (100 lM) and ABA (100 lM). Drought and H2O2 treatments led to earlier expression peaks of OsSIK1 than salt and ABA treatments. Water and cold treatments did not significantly affect the OsSIK1 expression.
    • The expression of the OsSIK1 gene was also examined under these treatments in another rice variety O. sativa ssp. japonica cv. Nipponbare, and the expression patterns were substantially comparable with those for the TP309 at the time points of treatments (Figure 1b). The results indicate that the OsSIK1 expression pattern is very similar in the two rice varieties under different treatments.
    • As shown in Figure 1(c), the strongest expression of OsSIK1 was found in the stem and panicle, and almost no expression was detected in the root and mature leaf.
    • Figure 1(d) shows that GUS driven by the OsSIK1 promoter was mainly expressed in young seedlings, nodes and inner vascular bundles. GUS activity was also high in the anthers of spikelets (Figure 1d). These results suggest that OsSIK1 is highly expressed in young seedlings, nodes, vascular bundles and anther.

Taken together, OsSIK1 promoter-GUS analysis revealed that OsSIK1 is expressed mainly in the stem and spikelet in rice. The expression of OsSIK1 is mainly induced by salt, drought and H2O2 treatments. Overexpression of OsSIK1 in rice can increase drought tolerance at the seedling stage and salt tolerance[1].

Evolution

Figure 2. Protein domain structure and phylogenetic analysis of LP2.(from reference [2]).
  • Two paralogues, OsRLK1 (Os06g0203800) and OsRLK2(Os02g0777400), were found in the rice genome. These homology with Arabidopsis RLKs AtER (63%), AtERL1 (70%) and AtERL2 (70%). In the kinase domain, the identities were 72, 84 and 82%, respectively. OsSIK1 has high similarity with ER family proteins from Arabidopsis, especially in the kinase domain. The three (ER) RLKs together control stomatal patterning, with specific family members regulating the specification of stomatal stem cell fate and the differentiation of guard cells in Arabidopsis[1].
  • But OsSIK1 and OsSIK2 share only 30.56% and 18.04% amino acid identities with LP2, respectively[2].
  • OsSIK1, OsSIK2 and LP2 proteins all belong to the LRR-RLK gene family, LP2 does not share significant primary sequence homology with OsSIK1 and OsSIK2. Phylogenetic analysis revealed that the three proteins are in different subgroups(Figure 2)[2].

Knowledge Extension

  • Receptor-like kinases (RLKs) play essential roles in plant growth, development and responses to environmental stresses. Most RLKs have kinase activity using Mn2+ as a co-factor[3][4][5]. Similarly, OsSIK1 has kinase activity in the presence of Mn2+. RLKs may have activity in the presence of other ions. Phosphorylation with various ions may indicate thatdifferent RLKs can function under unfavorable conditions or in response to different stresses.
  • ROS, partially reduced or activated derivatives of oxygen, are highly reactive and toxic, and can damage DNA, proteins and carbohydrates, resulting in cell death[6]. ROS also cause lipid peroxidation, cell membrane damage and MDA production. ROS production can increase under abiotic stresses[7][8][9].
Figure 3. Overview of plant receptor-like kinases (RLKs) and their functions.(from reference [10]).
  • The membrane-localized RLKs have been shown to control diverse signalling events (Fig. 3)[10], and these RLKs constitute the largest gene family in various plant genomes, with >600 members in Arabidopsis and 1100 members in rice, and are classified based on their extracellular structures. The RLKs regulate the homeostatic mechanisms underlying abiotic and biotic stress responses and have a major role in integrating environmental and plant hormone signallings.In addition, RLKs have been known to have a major role in integrating environmental and plant hormone signalling[10][11][12](Fig. 3).

Labs working on this gene

  • Plant Gene Research Center, National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
  • National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural

Sciences, Beijing 100081, PR China

  • National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, PR China

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Ouyang S Q, Liu Y F, Liu P, et al. Receptor‐like kinase OsSIK1 improves drought and salt stress tolerance in rice (Oryza sativa) plants[J]. The Plant Journal, 2010, 62(2): 316-329.
  2. ↑ 2.0 2.1 2.2 Wu F, Sheng P, Tan J, et al. Plasma membrane receptor-like kinase leaf panicle 2 acts downstream of the DROUGHT AND SALT TOLERANCE transcription factor to regulate drought sensitivity in rice[J]. Journal of experimental botany, 2014: eru417.
  3. ↑ Schulze-Muth P, Irmler S, Schröder G, et al. Novel Type of Receptor-like Protein Kinase from a Higher Plant (Catharanthus roseus) cDNA, GENE, INTRAMOLECULAR AUTOPHOSPHORYLATION, AND IDENTIFICATION OF A THREONINE IMPORTANT FOR AUTO-AND SUBSTRATE PHOSPHORYLATION[J]. Journal of Biological Chemistry, 1996, 271(43): 26684-26689.
  4. ↑ Liu G Z, Pi L Y, Walker J C, et al. Biochemical characterization of the kinase domain of the rice disease resistance receptor-like kinase XA21[J]. Journal of Biological Chemistry, 2002, 277(23): 20264-20269.
  5. ↑ He X J, Zhang Z G, Yan D Q, et al. A salt-responsive receptor-like kinase gene regulated by the ethylene signaling pathway encodes a plasma membrane serine/threonine kinase[J]. Theoretical and applied genetics, 2004, 109(2): 377-383.
  6. ↑ Mittler R, Vanderauwera S, Gollery M, et al. Reactive oxygen gene network of plants[J]. Trends in plant science, 2004, 9(10): 490-498.
  7. ↑ Zhu J K. Plant salt tolerance[J]. Trends in plant science, 2001, 6(2): 66-71.
  8. ↑ Mittler R. Oxidative stress, antioxidants and stress tolerance[J]. Trends in plant science, 2002, 7(9): 405-410.
  9. ↑ Xiong L, Schumaker K S, Zhu J K. Cell signaling during cold, drought, and salt stress[J]. The Plant Cell Online, 2002, 14(suppl 1): S165-S183.
  10. ↑ 10.0 10.1 10.2 Osakabe Y, Yamaguchi-Shinozaki K, Shinozaki K, et al. Sensing the environment: key roles of membrane-localized kinases in plant perception and response to abiotic stress[J]. Journal of experimental botany, 2013, 64(2): 445-458
  11. ↑ Shiu S H, Bleecker A B. Plant receptor-like kinase gene family: diversity, function, and signaling[J]. Science Signaling, 2001, 2001(113): re22.
  12. ↑ Diévart A, Clark S E. LRR-containing receptors regulating plant development and defense[J]. Development, 2004, 131(2): 251-261.


Structured Information

Retrieved from "https://ngdc.cncb.ac.cn/ricewiki/index.php?title=Os06g0130100&oldid=249143"