Gene Details:

Functional Descriptions:

  • These phenotypes suggest that combinatorial interactions between RISBZ1 and RPBF play an essential role during grain filling.
  • Compensation and interaction between RISBZ1 and RPBF during grain filling in rice.
  • Here, we show that OsLKR/SDH is directly regulated by major transcriptional regulators of seed storage protein (SSP) genes: the basic leucine zipper (bZIP) transcription factor (TF), RISBZ1, and the DNA-binding with one finger (DOF) transcription factor, RPBF.
  • This result was in contrast to the fact that a significant reduction of SSP was observed only when these transcription factors were simultaneously reduced, suggesting that RISBZ1 and RPBF regulate SSP genes and OsLKR/SDH with high and limited redundancy, respectively.
  • ) basic leucine Zipper factor RISBZ1 and rice prolamin box binding factor (RPBF) are transcriptional activators of rice seed storage protein (SSP) genes in vivo.
  • To ascertain the functions of these trans-activators in seed development, knock-down (KD) transgenic rice plants were generated in which the accumulation of RISBZ1 and RPBF was reduced in an endosperm-specific manner by co-suppression (KD-RISBZ1 and KD-RPBF).
  • Storage lipids were accumulated at reduced levels in KD-RISBZ1 and KD-RISBZ1/KD-RPBF seeds.
  • KD-RPBF and KD-RISBZ1/KD-RPBF seeds exhibited multi-layered aleurone cells.
  • The functional redundancy and compensation between RISBZ1 and RPBF possibly account for weak effects on the SSP levels in single KD mutants, and help maintain various processes during seed development in rice.
  • This study showed that OsbZIP58, a bZIP transcription factor, is a key transcriptional regulator controlling starch synthesis in rice endosperm.
  • OsbZIP58 was expressed mainly in endosperm during active starch synthesis.
  • OsbZIP58, a basic leucine zipper transcription factor, regulates starch biosynthesis in rice endosperm.
  • The RPBF gene is predominantly expressed in maturing endosperm and coordinately expressed with seed storage protein genes, and is involved in the quantitative regulation of genes expressed in the endosperm in cooperation with RISBZ1.
  • Five different basic leucine zipper cDNA clones, designated RISBZ1-5, have been isolated from a rice seed cDNA library.
  • RISBZ1 gene expression is restricted to the seed, where it precedes the expression of storage protein genes.
  • OsbZIP58 null mutants displayed abnormal seed morphology with altered starch accumulation in the white belly region and decreased amounts of total starch and amylose.
  • These findings indicate that OsbZIP58 functions as a key regulator of starch synthesis in rice seeds and provide new insights into seed quality control.
  • Reducing either RISBZ1 or RPBF decreased OsLKR/SDH levels, resulting in an increase in free lysine content in rice grain.
  • Overexpression of both transcription factors gave rise to much higher levels of expression than the sum of individual activities elicited by either RPBF or RISBZ1 alone.
  • Furthermore, OsbZIP58 was shown to bind directly to the promoters of six starch-synthesizing genes, OsAGPL3, Wx, OsSSIIa, SBE1, OsBEIIb, and ISA2, and to regulate their expression.
  • When the RISBZ1 promoter was transcriptionally fused to the beta-glucuronidase reporter gene and the chimeric gene was introduced into rice, the beta-glucuronidase gene is specifically expressed in aleurone and subaleurone layer of the developing endosperm.
  • These findings suggest that the specific expression of transcriptional activator RISBZ1 gene may determine the endosperm specificity of the storage protein genes.
  • A rice functional transcriptional activator, RISBZ1, responsible for endosperm-specific expression of storage protein genes through GCN4 motif.
  • Synergism between RPBF Dof and RISBZ1 bZIP activators in the regulation of rice seed expression genes.
  • OsLOL1, a C2C2-type zinc finger protein, interacts with OsbZIP58 to promote seed germination through the modulation of gibberellin biosynthesis in Oryza sativa.
  • Genome-wide identification of grain filling genes regulated by the OsSMF1 transcription factor in rice.
  • The results of this study suggest that OsSMF1 is one of the key transcription factors that functions in a wide range of seed developmental processes with different specific binding affinities for the three DNA-binding motifs.
  • OsSMF1 (previously called RISBZ1 or OsbZIP58) is known to interact with GCN4 motifs (TGA(G/C)TCA) to regulate seed storage protein synthesis, and it functions as a key regulator of starch synthesis.
  • OsSMF1 was shown to bind directly to the promoters of Os03g0168500 (GCN4 motif), patatin-like gene (GCN4 motif), α-globulin (ACGT motif), rice prolamin box-binding factor (RPBF) (ATGA motif), and ONAC024 (GCN4 and ACGT motifs) and to regulate their expression.
  • Here, we report that Opaque2 like transcription factor OsbZIP58 is a key factor regulating storage material accumulation under HT.
  • High temperature inhibits the accumulation of storage materials by inducing alternative splicing of OsbZIP58 during filling stage in rice.
  • Therefore, OsbZIP58 is a crucial gene in regulating storage material accumulation under HT and lower alternative splicing of OsbZIP58 may contribute to heat tolerance during grain filling.
  • The OsbZIP58 gene promotes expression of many seed storage protein genes and starch synthesis genes while inhibits expression of some starch hydrolyzing -amylase genes under HT.

Literature:

Gene Resources:

Sequences:

cDNA Sequence
  • >LOC_Os07g08420.1
    AAAATTGAAAAAAAAAAGAAAAAAAAAGAGAAGAAAAAAAAACCCATGGGTTGCGTAGCCGTAGCTTTCCCACCATTTCCTTCTCTCCGAAGCCTCCTCCTCTCCGCTTCCTCCCGCGAAACCAAATTCCAAAGCATTTGATCGAATTTCTCCCAAACTTTTCCAGCGTTTTCAATTTCGCCCCGATTTCGGTTCGAAAACCCCTCGCGAATTCATTTCAAACTCGTCCGAGAGCGCAATGGAGCACGTGTTCGCCGTCGACGAGATCCCCGACCCGCTGTGGGCTCCGCCGCCGCCGGTGCAGCCGGCGGCGGCCGCCGGAGTAGATGACGTCGGCGCGGTGAGCGGCGGCGGGTTGCTGGAGCGGTGCCCGTCGGGGTGGAACCTCGAGAGGTTTCTGGAGGAGCTCGACGGCGTCCCTGCACCGGCGGCGAGCCCGGACGGCGCGGCGATTTACCCTAGCCCGATGCCGGCGGCGGCGGCGGAGGCGGCGGCGCGCTGGAGTAGGGGCTACGGCGATCGTGAGGCGGTGGGGGTGATGCCCATGCCCGCGGCCGCGCTTCCGGCGGCGCCGGCGAGCGCGGCGATGGACCCCGTGGAGTACAACGCGATGCTGAAGCGGAAGCTGGACGAGGACCTCGCCACCGTCGCCATGTGGAGGGCCTCTGGTGCAATACATTCTGAGAGTCCTCTAGGCAATAAAACATCACTGAGTATAGTTGGTTCCATCCTGAGTTCACAGAAGTGCATTGAAGGTAACGGGATACTAGTGCAGACCAAGTTAAGTCCTGGCCCAAATGGAGGATCAGGCCCATATGTAAATCAAAATACAGATGCTCATGCCAAGCAAGCTACGAGTGGTTCCTCAAGGGAGCCATCACCATCAGAGGATGATGATATGGAAGGAGATGCAGAGGCAATGGGAAATATGATCCTTGATGAAGAAGATAAAGTGAAGAAAAGGAAGGAATCCAACCGGGAGTCAGCTAGACGCTCAAGAAGCAGAAAGGCAGCTCGCCTAAAAGACCTGGAGGAGCAGGTATCACTATTAAGGGTTGAAAACTCTTCTCTGTTGAGGCGTCTTGCTGATGCAAATCAGAAGTACAGTGCTGCTGCTATTGACAATAGGGTACTAATGGCAGACATTGAAGCCCTAAGAGCAAAGGTGAGGATGGCAGAGGAGAGTGTGAAGATGGTTACAGGGGCTAGACAACTTCACCAGGCCATTCCTGACATGCAATCTCCCCTCAATGTCAACTCTGATGCTTCTGTGCCGATCCAGAACAACAACCCAATGAACTACTTCTCCAACGCTAACAATGCCGGTGTTAACAGCTTCATGCACCAGGTTTCTCCAGCGTTCCAGATTGTGGATTCTGTCGAGAAGATTGACCCAACAGATCCAGTGCAGCTGCAGCAGCAACAGATGGCGAGCTTGCAGCATCTTCAGAATAGAGCTTGTGGTGGCGGCGCAAGTTCGAATGAATATACAGCATGGGGATCGTCTCTGATGGATGCAAATGAGCTTGTCAACATGGAGCTTCAGTAGTAGGAGCATATCCTAACAACATGATGAGAGCATTTGGAGGTGCAAATTTGCAACCTGCAAATGCTGTTTTGTAGTAGTAGTTGTTGTCGCTGTTTTTGTCTGAAACTGTAGTTTCTATGGATTTTGGACTTGCTGAGGAACATCTGCGGCTGTTGTTGTTTCAAATTGAGAAAATGAGGGACAATGGGACATGGTGGTCTCCCTTAATATAGCGAAAAATGGTTGGAATA
CDS Sequence
  • >LOC_Os07g08420.1
    ATGGAGCACGTGTTCGCCGTCGACGAGATCCCCGACCCGCTGTGGGCTCCGCCGCCGCCGGTGCAGCCGGCGGCGGCCGCCGGAGTAGATGACGTCGGCGCGGTGAGCGGCGGCGGGTTGCTGGAGCGGTGCCCGTCGGGGTGGAACCTCGAGAGGTTTCTGGAGGAGCTCGACGGCGTCCCTGCACCGGCGGCGAGCCCGGACGGCGCGGCGATTTACCCTAGCCCGATGCCGGCGGCGGCGGCGGAGGCGGCGGCGCGCTGGAGTAGGGGCTACGGCGATCGTGAGGCGGTGGGGGTGATGCCCATGCCCGCGGCCGCGCTTCCGGCGGCGCCGGCGAGCGCGGCGATGGACCCCGTGGAGTACAACGCGATGCTGAAGCGGAAGCTGGACGAGGACCTCGCCACCGTCGCCATGTGGAGGGCCTCTGGTGCAATACATTCTGAGAGTCCTCTAGGCAATAAAACATCACTGAGTATAGTTGGTTCCATCCTGAGTTCACAGAAGTGCATTGAAGGTAACGGGATACTAGTGCAGACCAAGTTAAGTCCTGGCCCAAATGGAGGATCAGGCCCATATGTAAATCAAAATACAGATGCTCATGCCAAGCAAGCTACGAGTGGTTCCTCAAGGGAGCCATCACCATCAGAGGATGATGATATGGAAGGAGATGCAGAGGCAATGGGAAATATGATCCTTGATGAAGAAGATAAAGTGAAGAAAAGGAAGGAATCCAACCGGGAGTCAGCTAGACGCTCAAGAAGCAGAAAGGCAGCTCGCCTAAAAGACCTGGAGGAGCAGGTATCACTATTAAGGGTTGAAAACTCTTCTCTGTTGAGGCGTCTTGCTGATGCAAATCAGAAGTACAGTGCTGCTGCTATTGACAATAGGGTACTAATGGCAGACATTGAAGCCCTAAGAGCAAAGGTGAGGATGGCAGAGGAGAGTGTGAAGATGGTTACAGGGGCTAGACAACTTCACCAGGCCATTCCTGACATGCAATCTCCCCTCAATGTCAACTCTGATGCTTCTGTGCCGATCCAGAACAACAACCCAATGAACTACTTCTCCAACGCTAACAATGCCGGTGTTAACAGCTTCATGCACCAGGTTTCTCCAGCGTTCCAGATTGTGGATTCTGTCGAGAAGATTGACCCAACAGATCCAGTGCAGCTGCAGCAGCAACAGATGGCGAGCTTGCAGCATCTTCAGAATAGAGCTTGTGGTGGCGGCGCAAGTTCGAATGAATATACAGCATGGGGATCGTCTCTGATGGATGCAAATGAGCTTGTCAACATGGAGCTTCAGTAG
Protein Sequence
  • >LOC_Os07g08420.1
    MEHVFAVDEIPDPLWAPPPPVQPAAAAGVDDVGAVSGGGLLERCPSGWNLERFLEELDGVPAPAASPDGAAIYPSPMPAAAAEAAARWSRGYGDREAVGVMPMPAAALPAAPASAAMDPVEYNAMLKRKLDEDLATVAMWRASGAIHSESPLGNKTSLSIVGSILSSQKCIEGNGILVQTKLSPGPNGGSGPYVNQNTDAHAKQATSGSSREPSPSEDDDMEGDAEAMGNMILDEEDKVKKRKESNRESARRSRSRKAARLKDLEEQVSLLRVENSSLLRRLADANQKYSAAAIDNRVLMADIEALRAKVRMAEESVKMVTGARQLHQAIPDMQSPLNVNSDASVPIQNNNPMNYFSNANNAGVNSFMHQVSPAFQIVDSVEKIDPTDPVQLQQQQMASLQHLQNRACGGGASSNEYTAWGSSLMDANELVNMELQ*