Genome-Wide Identification, Evolutionary Analysis, and Stress Responses of the GRAS Gene Family in Castor Beans

Abstract

Plant-specific GRAS transcription factors play important roles in regulating growth, development, and stress responses. Castor beans (Ricinus communis) are important non-edible oilseed plants, cultivated worldwide for its seed oils and its adaptability to growth conditions. In this study, we identified and characterized a total of 48 GRAS genes based on the castor bean genome. Combined with phylogenetic analysis, the castor bean GRAS members were divided into 13 distinct groups. Functional divergence analysis revealed the presence of mostly Type-I functional divergence. The gene structures and conserved motifs, both within and outside the GRAS domain, were characterized. Gene expression analysis, performed in various tissues and under a range of abiotic stress conditions, uncovered the potential functions of GRAS members in regulating plant growth development and stress responses. The results obtained from this study provide valuable information toward understanding the potential molecular mechanisms of GRAS proteins in castor beans. These findings also serve as a resource for identifying the genes that allow castor beans to grow in stressful conditions and to enable further breeding and genetic improvements in agriculture.

Genome-wide identification and expression of GRAS gene family members in cassava

“…In the present study, a total of 77 GRAS genes were identified in cassava. This number is lower than that in Malus domestica (127) [28], Populus (106) [20], and maize (86) [27] but higher than that in Arabidopsis (34) [20], rice (60) [20], Chinese cabbage (48) [19], Prunus mume (46) [21], tobacco (53) [22], castor (48) [23], grapevine (52) [24], Medicago truncatula (68) [25,26], pepper (50) [29], and tea plant (52) [30]. This variation in GRAS gene numbers might be related to gene duplication events or genome size [24].…”

“…It is noteworthy that some GRAS proteins considered to be species-specific in previous publications have homologs in cassava. For example, nine cassava MeGRAS genes (MeGRAS22, 23,27,28,29,30,31,34, and 66), together with PtGRAS20 (belong to "Pt20" subfamilly) and RcGRAS27 (29,889.m003282; belong to "Rc_GRAS" subfamily) which was previously regarded as species-specific subfamily [20,23]. They were also clustered with tomato SlGRAS22, which was clustered with pepper-specific "Ca_GRAS" subfamily [29].…”

“…To uncover the evolutionary relationships of the GRAS gene family in cassava and to help in their classification, a total of 211 GRAS proteins, comprising 77 from cassava, 33 from Arabidopsis, 50 from rice, 13 from castor bean, 13 from Populus, 13 from tomato, and 12 from tea plant (Additional file 1: Table S5) [18,20,23,29,48], were performed to construct an unrooted phylogenetic tree using maximum likelihood (ML) method by MEGA-X ( Fig. 1).…”

“…GRAS genes have recently been studied in various plant species, i.e., Arabidopsis [18], rice [18], Chinese cabbage [19], Populus [20], Prunus mume [21], tobacco [22], castor bean [23], grapevine [24], Medicago truncatula [25,26], maize [27], Malus domestica [28], pepper [29], and tea plant [30]. According to previous studies in Arabidopsis and rice [18], the GRAS family members can be classified into eight subfamilies: the DELLA, HAM, LAS, PAT1, SCR, SHR, SCL3, and LISCL subfamilies.…”

Descripción de semillas silvestres de Euphorbia strigosa Hook and Arn del estado de Nayarit, México

“…On the other hand, there is the hypothesis that seed size evolves as part of a spectrum of life history traits, including plant size, plant longevity, juvenile survival rate and time to reproduction (Moles y Westoby 2006). Or that gene complexes seek adaptation to the environment (Xu et al 2016). It is also thought that a reduction in the number of fruits causes an increase in the mass of individual seed (Jofuku et al 2005).…”