Characterization and Functional Divergence of a Novel DUF668 Gene Family in Rice Based on Comprehensive Expression Patterns

Abstract

The domain of unknown function (DUF) superfamily encodes proteins of unknown functions in plants. Among them, DUF668 family members in plants possess a 29 amino-acid conserved domain, and this family has not been described previously. Here, we report this plant-specific novel DUF668 gene family containing 12 OsDUF668 genes in rice (Oryza sativa) and 91 DUF668s for the other seven plant species. In our study, DUF668 genes were present in both dicot and monocot plants, indicating that DUF668 is a conserved gene family that originated by predating the dicot–monocot divergence. Based on the gene structure and motif composition, the DUF668 family consists of two distinct clades, I and II in the phylogenetic tree. Remarkably, OsDUF668 genes clustered on the chromosomes merely show close phylogenetic relationships, suggesting that gene duplications or collinearity seldom happened. Cis-elements prediction display that over 80% of DUF668s contain phytohormone and light responsiveness factors. Further comprehensive experimental analyses of the OsDUF668 family are implemented in 22 different tissues, five hormone treatments, seven environmental factor stresses, and two pathogen-defense related stresses. The OsDUF668 genes express ubiquitously in analyzed rice tissues, and seven genes show tissue-specific high expression profiles. All OsDUF668s respond to drought, and some of Avr9/Cf-9 rapidly elicited genes resist to salt, wound, and rice blast with rapidly altered expression patterns. These findings imply that OsDUF668 is essential for drought-enduring and plant defense. Together, our results bring the important role of the DUF668 gene family in rice development and fitness to the fore.

Genome-Wide Identification of the DUF668 Gene Family in Cotton and Expression Profiling Analysis of GhDUF668 in Gossypium Hirsutum Under Adverse Stress

“…4). Moreover, the number of genes from the two broad groups was basically the same in rice and some Poaceae [2]. Surprisingly, we found that in addition to GhDUF668-06 and GhDUF668-06, the DUF668 gene family contains not only the DUF668 domain but also the DUF3475 domain in G. arboreum, G. raimondii and G. hirsutum.…”

“…A previous study indicated that more DUF668 family genes exist in cotton than in monocot and dicot plants [2]. This might contribute to the double duplication of the cotton genome, or it might be that more genes were annotated in cotton than in other species [30,31,33,34].…”

“…Many studies have shown that genome-wide identi cation and expression analysis could help researchers understand the origin, diversity and biological functions of these DUF gene families [2,5,8,9,32]. In recent years, with the improvement of sequencing technology and the decrease in sequencing cost, cotton genome sequencing has been continuously improved and updated, laying the foundation for studying gene functions at the comprehensive genome level [28][29][30][31].…”

“…However, limited research has been conducted on this gene family. To date, the DUF668 gene family has been reported in only rice [2]. At present, all of the major cotton areas worldwide are threatened by varying degrees of salt, alkali, drought, cold damage and disease [23][24][25][26][27].…”

Morphological Physiological and Transcriptional Response to Low Nitrogen Stress in Populus Deltoides Marsh. Clones With Contrasting Nitrogen Use Efficiency

“…Among the hub genes, Podel.19G001200, which encodes a protein with a membrane attack complex component/perforin (MACPF) domain [50], and Podel.03G153500, which probable encodes a serine/threonine-protein kinase with a development and cell death (DCD) domain [51], are involved in cell development and programmed cell death. The domain of unknown function 668 (DUF668)-containing protein (Podel.02G021400) [52], the GRAM (from glucosyltransferases, Rab-like GTPase activators and myotubularins) domain-containing protein (Podel.06G003100) [53], and UDP-glycosyltransferases (Podel.04G076900) [54] are essential for plant defense against abiotic stress. The genes mentioned above might play an important role in the response to low N stress.…”