GIGANTEA regulates lateral root formation by modulating auxin signaling in Arabidopsis thaliana

Abstract

Lateral root (LR) formation is a vital organogenetic process that determines the root architecture in plants. The number of root branches governs the degree of anchorage, efficiency of nutrients acquisition, and water uptake. The molecular pathways involved in LR formation have been extensively studied in Arabidopsis thaliana ( At ). A plant hormone, Auxin, is a key regulator of root development and promotes LR formation in plants. A plethora of Arabidopsis genes have been identified to regulate LR initiation, patterning, and emergence processes. Recently, the involvement of flowering time control pathways and circadian clock pathways in LR development has come to light, but the connecting link between these processes is still missing. We have established that GIGANTEA (GI), a key component of photoperiodic flowering, can regulate the formation of LRs in Arabidopsis . GI is known to be involved in red light signaling and circadian clock signaling pathways. Here, we report that over-expression of GI enhances LR formation in red light in At . Real-time PCR analysis shows that GI positively regulates the transcription of TRANSPORT INHIBITOR RESPONSE 1 ( TIR1 ) which is an upstream component of auxin signaling. Furthermore, gi-100 mutant downregulates the LR initiation signaling gene, AUXIN RESPONSE FACTOR 7 ( ARF7 ), and its downstream target gene, LATERAL ORGAN BOUNDARIES-DOMAIN 16 ( LBD16 ). Hence, GI acts as a positive regulator of IAA14-ARF7-LBD16 modules during LR initiation. We have also checked the effect of GI on the expression of NAC1 and AIR3 genes which are controlled by TIR1 during LR formation. Our results show that GI induces the NAC1 transcription and its downstream gene, AIR3 expression, which leads to the enhancement of LR initiation. Taken together, our results suggest that GI controls the expression of TIR1 to govern auxin signaling during LR formation in presence of red light and GI can act as a link between circadian clock signaling, flowering time control pathways, light signaling, and lateral root development pathways.

Influence of Bradyrhizobium japonicum on the growth parameters and formation of the assimilation apparatus in E-gene isogenic lines of soybean

“…However, using the Phytozome database, the possibility of E2 gene expression (dominant state present in the Clark variety) in roots and symbiotic nodules was identified. Also, the homologous GIGANTEA gene in Arabidopsis thaliana is known to regulate lateral root development (Singh, 2022), potentially impacting mineral nutrient uptake. This regulation occurs through modulation of the auxin signaling pathway, a crucial hormone in symbiotic nodule formation (Wang, 2019).…”

NAC1 transcriptional activation of LDHA induces hepatitis B virus immune evasion leading to cirrhosis and hepatocellular carcinoma development

“…This study employed bioinformatics methods to provide initial evidence suggesting that NAC1 may regulate LDHA expression through transcriptional regulation. This regulatory mechanism potentially contributes to HBV immune escape, thus promoting the development of liver cirrhosis and HCC [ 36 ]. Understanding the accuracy and reliability of this mechanism is crucial for ensuring the credibility of scientific research [ 37 ].…”

IPD3, a master regulator of arbuscular mycorrhizal symbiosis, affects genes for immunity and metabolism of non-host Arabidopsis when restored long after its evolutionary loss

“…AM symbiosis affects flowering time in host plants, and the circadian clock is implicated in maintenance of the symbiosis itself as well as AM-mediated abiotic stress resistance (Hernandez and Allen 2013 ; Lee et al 2019 ; Bennett and Meek 2020 ; Liu et al 2022 ). In Arabidopsis , circadian rhythm genes are also known to act in microbiome construction, pathogen defense, development, and abiotic stress (Lee et al 2005 ; Nakamichi et al 2016 ; Newman et al 2022 ; Xu et al 2022 ; Singh 2022a , b ). Remarkably, in mosses, the sole group of nonAM plants that retain CSP genes, IPD3 specifically has been shown to mediate a stress-responsive reproductive transition (Kleist et al 2022 ).…”