Overexpression of PIF4 affects plant morphology and accelerates reproductive phase transitions in soybean

Abstract

Phytochrome‐interacting factor 4 acts as a signalling hub for integrating multiple environmental cues like light and temperature. While the function of PIF4 in the model plant Arabidopsis has been studied, there is limited knowledge regarding the role of PIF4 in agronomically important legume crop soybean. Here, we employed a constitutive overexpression approach to functionally characterise a soybean PIF4 homolog, GmPIF4b in a determinate short‐day cultivar, Bragg. Multiple sequence alignment of seven soybean PIF4 homologs (GmPIF4a‐g) with Arabidopsis PIF4 revealed the presence of an active phytochrome‐binding (APB) domain in the N‐terminal region of six soybean PIF4 homologs. Cis‐elements related to plant hormone biosynthesis, stress response, meristem and endosperm gene expression were located in the promoter region of soybean PIF4s. Interestingly, transgenic soybean plants carrying 35s::GmPIF4b::polyA construct showed reduced plant height, reduced leaf surface area, decreased branching, early flowering and faster transition from full‐bloom flowering stage to full maturity stage without any decline in yield. Further, pod colour of transgenic soybean plants changed to dark brown, whereas wild‐type plants showed tan or light brown pod colour. Clear hilum was observed in seeds obtained from transgenic plants as opposed to the dark or black hilum of wild‐type seeds. Transcripts of soybean florigens GmFT2a and GmFT5a were also elevated in transgenic plants. Collectively, our results suggest that GmPIF4b overexpression could affect phenotypes related to plant morphology and reproductive stages in soybean, and can be used as a gene target for soybean improvement programmes to ensure future food security.

Towards Developing Drought-smart Soybeans

“…Genetic engineering approaches offer viable opportunities for accelerated crop improvement (Khan et al, 2020;Lohani et al, 2020;Arya et al, 2021). Genes controlling traits, such as flowering time, disease resistance and lipid profile, have been identified and used as targets for soybean improvement (Haun et al, 2014;Arya et al, 2018;Ngaki et al, 2021).…”

Arabidopsis thaliana rosette habit is controlled by combined light and energy signaling converging on transcriptional control of the TALE homeobox gene ATH1

“…Present study shows that both absence of ATH1 and induced ATH1 expression leads to pronounced changes in PIF gene expression at the SAM associated with significant elongation or complete suppression of rosette internodes, respectively. PIF proteins have been associated with bolting time and/or stem internode elongation (Brock et al ., 2010; Todaka et al ., 2012; Galvāo et al ., 2019; Arya et al ., 2021; Jenkitkonchai et al ., 2021). Moreover, elongated rosette internodes can be observed in 35S::PIF4 plants (Fig.…”

Differentially expressed genes related to plant height and yield in two alfalfa cultivars based on RNA-seq

“…These genes may play a regulatory role in the process of plant height and internode elongation. Plant height and leaf area of transgenic soybean are decreased by overexpressing PIF4 ( Arya, Singh & Bhalla, 2021 ). The deletion of PIF1 and PIF3 results in an increase in plant height, longer internodes, and late flowering ( Hoang et al, 2021 ).…”