Initial Description of the Genome of Aeluropus littoralis, a Halophile Grass

Abstract

The use of wild plant species or their halophytic relatives has been considered in plant breeding programs to improve salt and drought tolerance in crop plants. Aeluropus littoralis serves as halophyte model for identification and isolation of novel stress adaptation genes. A. littoralis, a perennial monocot grass, grows in damp or arid areas, often salt-impregnated places and wasteland in cultivated areas, can survive periodically high water salinity, and tolerate high salt concentrations in the soil up to 1,100 mM sodium chloride. Therefore, it serves as valuable genetic resource to understand molecular mechanisms of stress-responses in monocots. The knowledge can potentially be used for improving tolerance to abiotic stresses in economically important crops. Several morphological, anatomical, ecological, and physiological traits of A. littoralis have been investigated so far. After watering with salt water the grass is able to excrete salt via its salt glands. Meanwhile, a number of ESTs (expressed sequence tag), genes and promoters induced by the salt and drought stresses were isolated, sequenced and annotated at a molecular level. Transfer of stress related genes to other species resulted in enhanced stress resistance. Here we describe the genome sequence and structure of A. littoralis analyzed by whole genome sequencing and histological analysis. The chromosome number was determined to be 20 (2n = 2x = 20). The genome size was calculated to be 354 Mb. This genomic information provided here, will support the functional investigation and application of novel genes improving salt stress resistance in crop plants. The utility of the sequence information is exemplified by the analysis of the DREB-transcription factor family.

Genome-wide analysis of the laccase (LAC) gene family in Aeluropus littoralis: A focus on identification, evolution and expression patterns in response to abiotic stresses and ABA treatment

“…The sequences were cross-checked with the Pfam database for the presence of three domains of laccases including CuRO_1_LCC_plant (cd13849), CuRO_2_LCC_plant (cd13875), and CuRO_3_LCC_plant (cd13897). Arabidopsis laccase protein sequences were aligned as queries against the Aeluropus Proteome and genome version 1 (Hashemi-Petroudi et al, 2022) using the local BLASTP and TBLASTN program, respectively. The resulting peptide sequences were verified with the blastP tool in NCBI and the Pfam database for the presence of conserved laccase (TIGR03389).…”

“…PlantCare (Lescot et al, 2002) was used to study cis-regulatory elements in the 1000 bp promoter region. The sequence information was retrieved from Aeluropus genome version 1 (Hashemi-Petroudi et al, 2022). The identified cis-regulatory elements were classified based on their function, and drawn as a graph.…”

Comprehensive Analysis of Calcium Sensor Families, CBL and CIPK, in <em>Aeluropus littoralis</em> and Its Expression Profile in Response to Salinity

“…Calcium sensors such as calcineurin B-like proteins (CBL) and CBL-interacting protein kinases (CIPKs) not only participate in the processes of plant growth and development, but they are also involved in stress responses [30]. In the present study, the available genome of A. littoralis was used as resource [38] and screened for the respective gene families. Six AlCBL genes and twenty AlCIPK genes were identified.…”

“…Therefore these species are of great interest to investigating the mechanisms of tolerance to salinity. This aims at mechanisms such as absorption, transport and homeostasis of ions, osmotic regulation and salt removal from leaves [37,38]. Although the cultivation of these plants is not an easy task, while the germplasm of halophyte plants is considered as a valuable source for providing genes resistant to environmental conditions, for the implementation of plant breeding programs [63].…”

“…Aeluropus littoralis as a halophyte model can grow under high salt concentrations [36,37]. Identifying genes related to resistance in plants such as A. littoralis, as a valuable germplasm, and determining their function can provide a better understanding of resistance mechanisms in plants [38]. According to the mentioned materials above, the genes of the CBL and CIPK family play a key role in responding to environmental stresses and regulating downstream signaling pathways, but these gene families have not been identified and investigated in A. littoralis.…”