FHY3 and FAR1 serve as positive regulators of the phyA-mediated far-red light signal pathway, influencing plant growth and development by regulating the expression of downstream genes. However, little is known about the FAR1/FHY3 family in Brassica species. A total of 21 members of the BnFAR1/FHY3 gene family were identified in the Brassica napus genome, exhibiting an uneven distribution across ten B. napus chromosomes. A phylogenetic analysis showed that the BnFAR1/FHY3 family could be divided into four subfamilies. Putative cis-elements in the BnFAR1/FHY3 promoter regions were also identified, which were potentially involved in phytohormone, light and abiotic stress responses (shading, low-temperature, etc.). Additionally, qRT-PCR results indicated that the expression levels of BnFAR1-10, BnFAR1-11, BnFAR1-21 and BnFAR1-4 decreased under shading stress. The expression of BnFAR1-10, BnFAR1-11 and BnFAR1-21 increased under low-temperature stress, whereas the expression of BnFAR1-4 did not change. In addition, the results of the tissue expression analysis showed that most of the genes exhibited the lowest expression in pollen and the highest expression in the 54-day silique. This study screened a batch of BnFHY3/BnFAR1 gene resources, which will contribute to further research on the functional characteristics of BnFHY3/BnFAR1 family members in growth, development and the stress response.

In plants, the multi-gene family of dual-function hexokinases (HXKs) plays an important role in sugar metabolism and sensing, that affects growth and stress adaptation. Sugarcane is an important sucrose crop and biofuel crop. However, little is known about the HXK gene family in sugarcane. A comprehensive survey of sugarcane HXKs, including physicochemical properties, chromosomal distribution, conserved motifs, and gene structure was conducted, identifying 20 members of the SsHXK gene family that were located on seven of the 32 Saccharum spontaneum L. chromosomes. Phylogenetic analysis showed that the SsHXK family could be divided into three subfamilies (group I, II and III). Motifs and gene structure were related to the classification of SsHXKs. Most SsHXKs contained 8–11 introns which was consistent with other monocots. Duplication event analysis indicated that HXKs in S. spontaneum L. primarily originated from segmental duplication. We also identified putative cis-elements in the SsHXK promoter regions which were involved in phytohormone, light and abiotic stress responses (drought, cold et al.). During normal growth and development, 17 SsHXKs were constitutively expressed in all ten tissues. Among them, SsHXK2, SsHXK12 and SsHXK14 had similar expression patterns and were more highly expressed than other genes at all times. The RNA-seq analysis showed that 14/20 SsHXKs had the highest expression level after cold stress for 6 h, especially SsHXK15, SsHXK16 and SsHXK18. As for drought treatment, 7/20 SsHXKs had the highest expression level after drought stress for 10 days, 3/20 (SsHKX1, SsHKX10 and SsHKX11) had the highest expression level after 10 days of recovery. Overall, our results revealed the potential biological function of SsHXKs, which may provide information for in-depth functional verification.

NCED proteins play a critical role in drought, salt, and cold stress responses through ABA biosynthesis in plants. However, little information is currently available regarding the NCED gene family in Brassica species. Twenty-six putative BjNCED genes were identified in the genome of Brassica juncea, and found to be distributed on 15 chromosomes. Phylogenetic analysis suggested that these members could be classified into six subfamilies. The putative cis-elements were identified in the promoter regions of these BjNCED genes, and thought to be related to phytohormones, light, and abiotic stress responses. qRT-PCR analysis of five genes (BjNCED1, BjNCED4, BjNCED7, BjNCED16 and BjNCED18) revealed that, under salt stress, BjNCED16 and BjNCED18 showed transient induction, whereas exogenous ABA produced gene-specific and time-dependent expression patterns, including pronounced induction of BjNCED16 at 24 h. Low-temperature treatment strongly induced four of the five examined genes at 6 h. Analysis of the BjNCED genes in this study provides a valuable foundation for future investigations into the functional roles of the BjNCED family in response to growth, development and stress.