Recombinant Oryza sativa subsp. japonica Squamosa promoter-binding-like protein 8 (SPL8)
Description
Introduction
The SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) gene family plays a crucial role in regulating plant architecture, panicle structure, and grain development in rice (Oryza sativa) . These genes are essential for crop improvement . Among these, Recombinant Oryza sativa subsp. japonica Squamosa Promoter-Binding-Like protein 8 (SPL8) is a transcription factor that influences various aspects of plant development and physiology .
Gene Function and Regulation
SPL8, as a member of the SPL family, significantly impacts plant architecture. Studies involving Medicago truncatula have shown that spl8 mutants exhibit increased biomass yield, while overexpression of SPL8 suppresses branching and reduces biomass yield . This suggests that SPL8 is a regulator of branching and biomass production .
Regulation by miR156: SPL genes are targets of microRNA156 (miR156), which affects the plant's development . The interaction between miR156 and SPL8 influences the timing of developmental transitions in plants .
Impact on Plant Development and Architecture
SPL8 affects several key developmental processes:
Functional Studies and Experimental Evidence
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Medicago truncatula (MtSPL8) Studies: Functional characterization of SPL8 in M. truncatula revealed that spl8 mutants have increased biomass yield. Overexpression of MtSPL8 suppressed branching, with some transgenic plants showing very few branches, especially lateral branches .
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MsSPL8 Studies in Alfalfa: Overexpression of MsSPL8 in alfalfa resulted in decreased branches, similar to the effects observed in MtSPL8 overexpression studies. Down-regulation of MsSPL8 led to increased forage biomass .
Role in Hormone Signaling
While direct evidence linking SPL8 to hormone signaling pathways in rice is limited in the provided context, other SPL genes interact with hormone-related pathways. For example, OsCYP85A1, when overexpressed, increases endogenous brassinosteroid (BR) levels, promoting growth and biomass production .
SPL8 and Biomass Production
SPL8's role in biomass production is evident from studies in M. truncatula and alfalfa. In M. truncatula, spl8 mutants showed increased biomass, while overexpression suppressed branching and reduced biomass yield . Similarly, down-regulation of MsSPL8 in alfalfa increased forage biomass .
