Hormonal control of the plant cell cycle

Abstract

Plant organogenesis is essentially a post-embryonic process that requires a strict balance between cell proliferation and differentiation. This is subject to a complex regulatory network which, in some cases, depends on the action of a variety of plant hormones. Of these, auxins and cytokinins are those best documented as impinging directly on cell cycle control.However, increasing evidence is accumulating to indicate that other hormones also have an impact on cell cycle control by influencing the availability of cell cycle regulators. In this article, we review the results that point to the variety of situations in which cell cycle progression is controlled by phytohormones.

Transcriptome Analysis of Proliferating Arabidopsis Endosperm Reveals Biological Implications for the Control of Syncytial Division, Cytokinin Signaling, and Gene Expression Regulation

“…Conversely, ABA levels were low at anthesis and slowly increased to peak values at 12 DAP or later, depending on the cultivar. These observations are consistent with the idea that during the early syncytial stage of development (0-4 d in rice) ethylene levels are high, which may inhibit ABA biosynthesis (Ghassemian et al, 2000;del Pozo et al, 2005). It remains to be elucidated whether ethylene and ABA have an antagonistic effect during early endosperm development.…”

Impact of Water Management on Rice Varieties, Yield, and Water Productivity under the System of Rice Intensification in Southern Taiwan

“…Thakur et al [5] highlighted that SRI leaves had higher light utilization capacity and a greater photosynthetic rate which ensures sufficient supply of assimilates to the roots for their development and longevity. Bigger roots and greater root activity under AWD-SRI translates to increased root oxidation activity and root-sourced cytokinins [48], which are believe to play a major role in promoting cell division and thereby delaying leaf senescence [49,50].…”

Divide and conquer: development and cell cycle genes in plant transformation

“…Auxin receptors and/or transporters affect the G1-S transition Plant tissues have the potential to regenerate through organogenesis or somatic embryogenesis, depending on the type and proportion of auxins and cytokinins present in culture media; these same two hormones control the cell cycle [5]. In tobacco cells, the ubiquitin proteolytic system (SCF) is required for chromatin decondensation and reactivation of S phase [19] -in these cells auxin appears to trigger E2Fc degradation through the AXR1-SCF pathway [5], where AXR1 encodes a protein involved in RUB (Ub-related) modification of CUL1 and, therefore, is a regulator of the E3 ligase-SCF activity.…”

“…In tobacco cells, the ubiquitin proteolytic system (SCF) is required for chromatin decondensation and reactivation of S phase [19] -in these cells auxin appears to trigger E2Fc degradation through the AXR1-SCF pathway [5], where AXR1 encodes a protein involved in RUB (Ub-related) modification of CUL1 and, therefore, is a regulator of the E3 ligase-SCF activity. As discussed above, E2Fc prevents the progression through G1-S; therefore, its degradation facilitates G1-S transition [5]. SCF complex also catalyzes the destruction of Aux-IAA transcription factors, triggered by the interaction of auxin with the transport-inhibitor response protein 1 (TIR1) [44].…”

“…Phytohormones, such as auxins, are powerful tools to stimulate cell division and modify the competence of cells [5] but they are often inadequate for promoting efficient transformation. Zuo et al [6] summarized the potential uses of cyclin D3, histone H2A (H2A), cytokinin synthesis and receptor genes to improve regeneration and as a means to generate marker-free transgenic plants: they identified several opportunities as to how these genes might be harnessed to improve transformation systems.…”