Analysis of a radiation-induced dwarf mutant of a warm-season turf grass reveals potential mechanisms involved in the dwarfing mutant

Abstract

Zoysia matrella [L.] Merr. is a widely cultivated warm-season turf grass in subtropical and tropical areas. Dwarf varieties of Z. matrella are attractive to growers because they often reduce lawn mowing frequencies. In this study, we describe a dwarf mutant of Z. matrella induced from the 60Co-γ-irradiated calluses. We conducted morphological test and physiological, biochemical and transcriptional analyses to reveal the dwarfing mechanism in the mutant. Phenotypically, the dwarf mutant showed shorter stems, wider leaves, lower canopy height, and a darker green color than the wild type (WT) control under the greenhouse conditions. Physiologically, we found that the phenotypic changes of the dwarf mutant were associated with the physiological responses in catalase, guaiacol peroxidase, superoxide dismutase, soluble protein, lignin, chlorophyll, and electric conductivity. Of the four endogenous hormones measured in leaves, both indole-3-acetic acid and abscisic acid contents were decreased in the mutant, whereas the contents of gibberellin and brassinosteroid showed no difference between the mutant and the WT control. A transcriptomic comparison between the dwarf mutant and the WT leaves revealed 360 differentially-expressed genes (DEGs), including 62 up-regulated and 298 down-regulated unigenes. The major DEGs related to auxin transportation (e.g., PIN-FORMED1) and cell wall development (i.e., CELLULOSE SYNTHASE1) and expansin homologous genes were all down-regulated, indicating their potential contribution to the phenotypic changes observed in the dwarf mutant. Overall, the results provide information to facilitate a better understanding of the dwarfing mechanism in grasses at physiological and transcript levels. In addition, the results suggest that manipulation of auxin biosynthetic pathway genes can be an effective approach for dwarfing breeding of turf grasses.

Comprehensive transcriptomic analysis of age-, dark-, and salt-induced senescence reveals underlying mechanisms and key regulators of leaf senescence in Zoysia japonica

“…Between 73.1% and 95.3% of the total clean reads from each sample were mapped to the Z. japonica reference genome ( Supplementary Table 4 ). However, the average matching rate of transcripts was approximately 75.2%, which is relatively low ( Lin et al., 2020 ). Visual examination of the structural annotation data of reads mapped to the Z. japonica genome revealed that this low mapping rate was due to inaccurate transcript annotation.…”

Transcriptome and WGCNA reveal hub genes in sugarcane tiller seedlings in response to drought stress

“… 67 . Soluble protein was assessed with coomassie brilliant blue G250 staining method 68 . The starch content was determined by an anthrone colorimetric method 69 .…”

“…Proline content was detected using the sulfosalicylic acid method according to Elasad et al 67 . Soluble protein was assessed with coomassie brilliant blue G250 staining method 68 . The starch content was determined by an anthrone colorimetric method 69 .…”

A Survey of Enhanced Cold Tolerance and Low-Temperature-Induced Anthocyanin Accumulation in a Novel Zoysia japonica Biotype

“…Whole transcriptome analysis based on next-generation sequencing technologies has developed as a useful approach for finding and identifying genes involved in abiotic stress resistance in recent years, drastically enhancing our understanding of the interaction between plant and environment. To date, the NCBI database holds 11 transcriptomic BioProjects for Zoysia species, including 8 for Z. japonica , 2 for Z. matrella [ 7 , 8 ], and 1 for Z. macrostachya [ 9 ]. Among the eight transcriptomic studies on Z. japonica , two focused on spike pigmentation [ 10 ], one on responses to pathogen invasion [ 11 ], and the others on responses to abiotic stresses, including aluminum, wounding [ 12 ], salt [ 13 , 14 ] and low-temperature [ 15 ].…”