Gene expression study on coconut under drought stress
To study gene expression in coconut under drought stress. Two Sri Lankan coconut cultivars, Sri Lankan Tall, the main coconut cultivar grown in Sri Lanka) and Ambakelle Special (AS), the promising drought-tolerant cultivar were used for this study. Coconut seedlings were grown in a rain-out shelter at the Coconut Research Institute in Sri Lanka. The experiment was conducted in a Completely Randomized Design (CRD) with six replicates per treatment combination.Seven-month-old seedlings planted in 100L plastic containers with a potting medium. Each of the two cultivars was represented by 12 seedlings, resulting in a total of 24 seedlings. Initially, all seedlings were maintained under well-watered conditions for two months to establish their growth. Subsequently, half of the seedlings (6 from each cultivar) were subjected to simulated moisture stress by withholding irrigation for up to 60 days, while the other half continued to be maintained under well-watered conditions.Fifty-five days after the introduction of drought conditions, young leaf samples were collected from a total of 12 seedlings across the two cultivar groups. In each cultivar, three drought-treated seedlings and three well-watered seedlings were selected for sample collection. Total RNA was isolated from each frozen sample (1 g) using a modified CTAB protocol. However, due to the inability to extract an adequate amount of quality RNA from drought-treated samples from both cultivars, only two samples from each treatment (two well-watered and two drought treated from each cultivar) proceed to cDNA synthesis.cDNA synthesis and library preparation were performed using Oxford nanopore ONT's ligation kit (SQK-LSK109), following the supplier protocol. Oxford nanopore sequencing was employed, followed by data cleaning and base calling.