Genome-Wide Identification of Switchgrass Laccases Involved in Lignin Biosynthesis and Heavy-Metal Responses

Abstract

Plant laccase genes belong to a multigene family, play key roles in lignin polymerization, and participate in the resistance of plants to biotic and abiotic stresses. Switchgrass is an important resource for forage and bioenergy production, yet information about the switchgrass laccase gene family is scarce. Using bioinformatic approaches, a genome-wide analysis of the laccase multigene family in switchgrass was carried out in this study. In total, 49 laccase genes (PvLac1 to PvLac49) were identified; these can be divided into five subclades, and 20 of them were identified as targets of miR397. The tandem and segmental duplication of laccase genes on Chr05 and Chr08 contributed to the expansion of the laccase family. The laccase proteins shared conserved signature sequences but displayed relatively low sequence similarity, indicating the potential functional diversity of switchgrass laccases. Switchgrass laccases exhibited distinct tissue/organ expression patterns, revealing that some laccases might be involved in the lignification process during stem development. All five of the laccase isoforms selected from different subclades responded to heavy metal. The immediate response of lignin-related laccases, as well as the delayed response of low-abundance laccases, to heavy-metal treatment shed light on the multiple roles of laccase isoforms in response to heavy-metal stress.

Characterization of Peroxidase and Laccase Gene Families and In Silico Identification of Potential Genes Involved in Upstream Steps of Lignan Formation in Sesame

“…The most abundant laccases were observed in Swetha (n = 56), followed by Zhongzhi13 (n = 48), Goenbaek (n = 45), Baizhima (n = 42), Yuzhi11 (n = 40), and Mishuozhima (n = 35). Similar laccases counts were observed in land plants Prunus persica (n = 48) [ 82 ], Panicum virgatum (n = 49) [ 83 ], and Solanum melongena (n = 42) [ 84 ]; a lower number of laccase genes was reported in A. thaliana (n = 17) [ 85 ].…”

“…In contrast, only a tandem duplication pattern was detected in Solanum melongena with 16 laccase genes [ 84 ]. In Panicum virgatum , both tandem and segmental duplications of laccase genes were found [ 83 ].…”

The Citrus Laccase Gene CsLAC18 Contributes to Cold Tolerance

“…Additionally, our previous study revealed that the LTR motif ( cis -acting element involved in low-temperature responsiveness) was predicted to be located in the promoter regions of eight chilling-responsive CsLACs [ 18 ]. Moreover, low-temperature cis -elements were found in the promoters of 8 LACs from Brassica napus [ 29 ], 11 LACs from eggplant [ 17 ], 21 LACs from switchgrass [ 30 ], 12 LACs from tea plant [ 31 ], 45 LACs from wheat [ 32 ], and 16 LACs from peach [ 33 ]. Therefore, the above results indicate that low-temperature cis -elements are essential for the LACs to respond to cold stress.…”

Grass lignin: biosynthesis, biological roles, and industrial applications

“…Research into heavy metal tolerance is increasing as major cereal crops are experiencing significant yield loss due to irrigation containing zinc (Zn), ferrous iron (Fe), nickel (Ni), copper (Cu), cadmium (Cd), chromium (Cr), and lead (Pb) from industrial runoff (Mir et al, 2021;Riyazuddin et al, 2022;Skuza et al, 2022;Li et al, 2022b;Xu et al, 2023). Mounting evidence suggests cell wall thickening of both woody and herbaceous plants contributes a partial but significant exclusion barrier where heavy metals are sequestered via ion exchange and chelation with methylesterified pectins, phenolic acids, organic acids, and ROS (Krzeslowska, 2011;Parrotta et al, 2015;Berni et al, 2019;Gao et al, 2021;Sytar et al, 2021) (Table 1).…”