PagGRF11 Overexpression Promotes Stem Development and Dwarfing in Populus

Abstract

Poplar is not only an important woody plant, but also a model species for molecular plant studies. We identified PagGRF11 (pAxG07Gg0005700), a homolog of the Arabidopsis AtGRF1 (AT4G37740) and AtGRF2 (AT2G22840) gene. We transformed the poplar clone “84K” with PagGRF11, and the transgenic overexpressed plants (PagGRF11-OE) showed plant height reduction (dwarfing), stem diameter increase, internode shortening, and larger leaf area. The Arabidopsis overexpression line grf-oe (Overexpression of PagGRF11 in Arabidopsis), mutant line atgrf (a loss-of-function mutant of the AtGRF1 gene of Arabidopsis thaliana), and mutant trans-complementary line atgrf+oe (overexpression of PagGRF11 in mutant plants (atgrf)) also showed different leaf size phenotypes. Further, tissue sections revealed that increased xylem production was the main cause of stem thickening. Transcriptome differential expression analysis of PagGRF11 overexpressed and control plants showed that PagGRF11 promoted CCCH39(C3H39) expression. The expression profile of CCCH39 in different tissues showed that it was highly expressed in xylem. Yeast single hybrid and instantaneous double luciferase assay results showed that PagGRF11 directly transcribed and activated CCCH39 expression through interaction with cis-acting element GARE (TCTGTTG), thus promoting xylem development. This is the first finding that GRF positively regulates xylem development through CCCH39 expression activation and further suggests that PagGRF11 is a potential target for increasing wood yield.

Allelic variations of WAK106‐E2Fa‐DPb1‐UGT74E2 module regulate fibre properties in Populus tomentosa

“…Another possibility for this condition is that the changes in lignin composition reduced the lignocellulosic biomass recalcitrance to enzymatic hydrolysis, thus leading to easily dissociate of cellulose and accessibility of enzymes to cellulose (Zhang et al ., 2019 ; Zoghlami and Paës, 2019 ), and we will investigate this possibility of PtoDPb1 for enzymatic properties in the future. Similar findings have been reported in studies involving the overexpression of PtoMYB74 and GRF11 , which led to elevated levels of cellulose and lignin in Populus (Li et al ., 2018 ; Tian et al ., 2022 ). Additionally, since glucose is the major composition of cellulose, and a positive correlation between glucose and cellulose content was observed in the study, which was consistent with previous study (Yoo et al ., 2017 ; Zhang et al ., 2019 ; Zoghlami and Paës, 2019 ).…”

Genome-Wide Identification and Expression Analysis of Growth-Regulating Factors in Eucommia ulmoides Oliver (Du-Zhong)

“…In maize, the high accumulation of ZmGRF1 transcripts resulting from a mutation in the miR396s target sites led to an increase in the leaf blade size [23]. Additionally, the involvement of plant GRFs has also been demonstrated in various biological processes, including xylem development, reproductive organ development, flowering, stress response, and even plant longevity [2,[24][25][26][27][28][29][30][31].…”