Agave, monocotyledonous succulent plants, is endemic to arid regions of North America, exhibiting exceptional tolerance to their xeric environments. They employ various strategies to overcome environmental constraints, such as crassulacean acid metabolism, wax depositions, and protective leaf morphology. Genomic resources of Agave species have received little attention irrespective of their cultural, economic and ecological importance, which so far prevented the understanding of the molecular bases underlying their adaptations to the arid environment. In this study, we aimed to elucidate molecular mechanism(s) using transcriptome sequencing ofA. sisalana. Ade novoapproach was applied to assemble paired-end reads. The expression study unveiled 3,095 differentially expressed unigenes between well-irrigated and drought-stressed leaf samples. Gene ontology and KEGG analysis specified a significant number of abiotic stress responsive genes and pathways involved in processes like hormonal responses, antioxidant activity, response to stress stimuli, wax biosynthesis, and ROS metabolism. We also identified transcripts belonging to several families harboring important drought-responsive genes. Our study provides the first insight into the genomic structure ofA. sisalanaunderlying adaptations to drought stress, thus providing diverse genetic resources for drought tolerance breeding research.

Cotton ( Gossypium hirsutumL.) fiber initiation from ovule epidermal cells happen from 0 to 5 DPA, invertase (INV) and sucrose synthase (SuSy) are crucial for fiber initiation, cell...

Heat shock Protein (HSP) expression is the plants’ responses to high temperature. We analysed the HSP70 gene family in Agave sisalana transcriptome to understand its expression under heat stress. A total of 167 genes were identified as heat shock protein genes. Among them; 74, 39 and 25 belong to the HSP70, HSP20 HSP90 respectively and multiple sequence alignment of conserved domain proteins of AsHSP70 showed that they are highly conserved. Fifty-two AsHSPs were classified into three major classes according to their structural characteristics. Phylogenetic analysis indicated that orthologs from Agave deserti and Agave tequilana species were distributed among the three classes; which revealed the diverse expression of HSP70 gene family. In silico subcellular localisation of AsHSP, suggested that its interaction is quite diverse in target cells and active signalling pathways. Transcripts identified and named as B1, B3, B5, B7, B9, B11, B13, B15, B17 and B19 were validated through Nested PCR. Significant difference in the expression pattern of target gene was revealed after normalisation with GAPDH. Gene expression was up-regulated with some exceptions as down-regulated. In silico analysis of HSP70 gene family identified from A. sisalana suggests that genetic transformation of this gene will induce heat tolerance in transgenic crops.