Global Analysis of Gene Expression Profiles in Physic Nut (Jatropha curcas L.) Seedlings Exposed to Salt Stress

Abstract

BackgroundSalt stress interferes with plant growth and production. Plants have evolved a series of molecular and morphological adaptations to cope with this abiotic stress, and overexpression of salt response genes reportedly enhances the productivity of various crops. However, little is known about the salt responsive genes in the energy plant physic nut (Jatropha curcas L.). Thus, excavate salt responsive genes in this plant are informative in uncovering the molecular mechanisms for the salt response in physic nut.Methodology/Principal FindingsWe applied next-generation Illumina sequencing technology to analyze global gene expression profiles of physic nut plants (roots and leaves) 2 hours, 2 days and 7 days after the onset of salt stress. A total of 1,504 and 1,115 genes were significantly up and down-regulated in roots and leaves, respectively, under salt stress condition. Gene ontology (GO) analysis of physiological process revealed that, in the physic nut, many “biological processes” were affected by salt stress, particular those categories belong to “metabolic process”, such as “primary metabolism process”, “cellular metabolism process” and “macromolecule metabolism process”. The gene expression profiles indicated that the associated genes were responsible for ABA and ethylene signaling, osmotic regulation, the reactive oxygen species scavenging system and the cell structure in physic nut.Conclusions/SignificanceThe major regulated genes detected in this transcriptomic data were related to trehalose synthesis and cell wall structure modification in roots, while related to raffinose synthesis and reactive oxygen scavenger in leaves. The current study shows a comprehensive gene expression profile of physic nut under salt stress. The differential expression genes detected in this study allows the underling the salt responsive mechanism in physic nut with the aim of improving its salt resistance in the future.

Ecological speciation in sympatric palms: 1. Gene expression, selection and pleiotropy

“…When DCL1 is knocked out in Arabidopsis , flowering is delayed (Schmitz et al ., ). DCL4 is involved with post‐transcriptional gene silencing through the biogenesis of small interfering RNA associated with many processes including juvenile‐to‐adult phase transition (Xie et al ., ) and cell‐to‐cell gene silencing (Dunoyer et al ., ) in Arabidopsis . In Pyrenean Rocket, DCL4 was found to be under selection during rapid adaptation to novel environments (Vandepitte et al ., ). NAC072 , also known as RD26 , encodes a transcription factor induced in response to desiccation and salinity in the Physic Nut (Zhang et al ., ). Overexpression of NAC072 in Arabidopsis significantly increases drought tolerance (Tran et al ., ). SAL1 encodes a bifunctional enzyme with 3′(2′),5′‐bisphosphate nucleotidase and inositol polyphosphate 1‐phosphatase activities; Arabidopsis mutants have altered abiotic stress tolerance (Xiong et al ., ; Wilson et al ., ) and increased salt sensitivity in seedlings (Chen et al ., ). TIC is a circadian regulator that integrates developmental, metabolic and environmental signals (Sanchez‐Villarreal et al ., ); loss of TIC function results in late flowering and increased drought tolerance in Arabidopsis (Sanchez‐Villarreal et al ., ).…”

“…In Pyrenean Rocket, DCL4 was found to be under selection during rapid adaptation to novel environments (Vandepitte et al, 2014). (iv)NAC072, also known as RD26, encodes a transcription factor induced in response to desiccation and salinity in the Physic Nut (Zhang et al, 2014). Overexpression of NAC072 in Arabidopsis significantly increases drought tolerance (Tran et al, 2004).…”

Gene expression profiling identifies pathways involved in seed maturation of Jatropha curcas

“…In addition, whole genome sequencing was applied to identify protein-encoding genes, which could help in improving the traits of interest (e.g. oil composition) of J. curcas [19][20][21][22][23][24].Considering that Jatropha flowering and fruit-bearing are practically continuous, the simultaneous presence of mature and immature fruit on the same plant provides a unique opportunity to collect seeds in different stages of maturation of this open-pollinated plant. Therefore, to obtain an overview of transcripts associated with all the seed maturation stages that are potentially involved in seed maturation under the same environmental condition, we performed the following analyses; 1)…”

Advances in Plant Tolerance to Abiotic Stresses

“…The biosynthesis and transport of trehalose and raffinose is particularly relevant in drought stress response. More recently, genes encoding for trehalose and raffinose biosynthesis were significantly upregulated in the roots and leaves of Jatropha curcas under drought [48], suggesting that these compounds may have major impacts on osmotic adjustment and ROS scavenging during drought stress. The same authors indicated that dozens of genes involved in wax biosynthesis, including KCS and WSD, and their regulators (e.g., MYB96, CER) were upregulated more than four-fold in leaves under drought conditions.…”