ENHANCED GRAVITROPISM 2 (EGT2/ HORVU.MOREX.r3.5HG0447830), f...

created [InstanceEdit:9916142] Naithani, Sushma, 2024-07-23
dbId 9916109
displayName ENHANCED GRAVITROPISM 2 (EGT2/ HORVU.MOREX.r3.5HG0447830), f...
literatureReference
modified [InstanceEdit:9916282] Naithani, Sushma, 2024-07-23
schemaClass Summation
text ENHANCED GRAVITROPISM 2 (EGT2/ HORVU.MOREX.r3.5HG0447830), first discovered in barley (Hordeum vulgare), is a STERILE ALPHA MOTIF (SAM) domain containing transcriptional regulator of root growth angle (Kirschner et al., 2021; PMID: 34446550 ). The rice ortholog of EGT2 is Os12g0514600/ LOC_Os12g32992 and has not been functionally charatectized (no name in RAP-DB). The barley egt2 displays hypergravitropic root phenotype (with root angles at least 50% narrower than wild-type plants and an enhanced gravitropic response to gravistimulation). Thus,EGT2 is a negative regulator of root growth angle and plays a role in antigravitrophic offset (Guo et al., 2023; PMID: 36604847). Arabidopsis homolog of EGT2 is AtSAM5 (AT3G07760) and mutants of AtSAM5 also have narrower lateral root angles (Johnson et al., 2022; PMID: 35685275). Thus, EGT2 is likely to be an evolutionary conserved regulator of seminal and lateral root growth angle in monocots and dicots. The mutations in the barley EGT2 gene have no effect on gravity perception or statolith sedimentation and do not have disrupted auxin signaling, thus, this gene works downstream of auxin-mediated cell signaling. In barely, EGT2 is shown to express in the whole root tip, including the root cap, meristem, and elongation zone (Kirschner et al., 2021; PMID: 34446550) and egt2 mutant displays defects in the cell wall?related processes in the Elongation Zone (Kirschner et al., 2021; PMID: 34446550). The transcriptome analysis of egt2 mutant and wild-type plants suggested that EGT2 is likely to control transcription of the molecular networks associated with gravitropic bending (Guo et al., 2023; PMID: 36604847). EGT2 may play a role in the same pathway as EGT1; however, these two genes do not regulate each other (Kirschner et al., 2021; PMID: 34446550, and Guo et al., 2023; PMID: 36604847).