Sequence and functional analysis of a TERMINAL FLOWER 1 homolog fromBrassica juncea: a putative biotechnological tool for flowering time adjustment

Abstract

Flowering time is an important agricultural trait of the oil crop Brassica juncea (B. juncea), as accelerated flowering enables avoidance of terminal drought leading to increased yields. One gene known to control flowering time is TERMINAL FLOWER 1 (TFL1), which belongs to a family of phosphatidylethanolamine binding proteins, which can either repress or promote flowering time.Here, a TFL1 homolog, named BjTFL1, has been isolated from B. juncea, which shared 95% amino acid identity with TFL1 from Arabidopsis thaliana. Sequence analysis predicts the BjTFL1 protein contains the ligand-binding site, conserved motifs and other amino acid residues that are critical for TFL1 function. Confirming this as a functional TFL1 orthologue, overexpression of BjTFL1 under the control of the constitutive 35S promoter in Arabidopsis delayed flowering time. As a proof-ofconcept to investigate its utility to shorten flowering time, an RNAi construct containing a partial sequence of BjTFL1 was transformed into Arabidopsis. Transcript analysis demonstrated the downregulation of endogenous AtTFL1. Moreover, the RNAi BjTFL1 transgenic lines were early flowering and had fewer rosette and cauline leaves compared to wild-type. Therefore, this BjTFL1 RNAi transgene could be used as a biotechnological tool to reduce flowering time in Brassica juncea in a bid to improve agricultural performance.

QTL analysis of flowering‐related traits by specific length amplified fragment sequencing in melon

“…At present, some FT approximate genes have been found in many horticultural crops such as melon (Zhang & Zhang, 2020), ginkgo ( Ginkgo biloba L.) (Wang et al., 2019), and white lupin ( Lupinus albus L.) (Rychel et al., 2019). Besides the FT gene, TFL1 (Zhao et, al., 2018; Khanouki et al., 2020), NGATHA1 (Guo et, al., 2020), LFY (Qi et al., 2015), FLC (Kumar et al., 2016), and SOC1 (Liu et al., 2020) were also important genes that regulated flowering time. Ffn2.1 and Ffn2.2 were closely related to the first flower node in pepper ( Capsicum annuum L.) (Zhang et al., 2019).…”

“…The flowering process of higher plants is regulated by external conditions such as light, temperature, moisture, and nutrition, as well as a complex network of flowering promotion and suppression genes (Guo et al., 2020; Khanouki & Millar. et al., 2020; Kumar et al., 2016; Lu et al., 2014; Qi et al., 2015; Zhao et al., 2018). The flower opening time or the length of flowering time can affect fruit ripening, harvest time, and yield (Fisogni et al., 2011; Zhang et al., 2019).…”

“…It is also an essential marker of the transformation of plants from basic vegetative growth to reproductive growth. The flowering process of higher plants is regulated by external conditions such as light, temperature, moisture, and nutrition, as well as a complex network of flowering promotion and suppression genes (Guo et al, 2020;Khanouki & Millar. et al, 2020;Kumar et al, 2016;Lu et al, 2014;Qi et al, 2015;Zhao et al, 2018).…”