Molecular insights into photosynthesis and carbohydrate metabolism in Jatropha curcas grown under elevated CO2 using transcriptome sequencing and assembly

Abstract

Jatropha curcas L. (Family – Euphorbiaceae) is a perennial tree of special interest due to its potential as a biofuel plant with high carbon sequestration. In this study, physiological investigations coupled with transcriptomics in relation to photosynthesis were evaluated in Jatropha grown under ambient (395 ppm) and elevated (550 ppm) CO2 atmosphere. Morphophysiological analysis revealed that Jatropha sustained enhanced photosynthesis during its growth under elevated CO2 for one year which might be linked to improved CO2 assimilation physiology and enhanced sink activity. We sequenced and analyzed the leaf transcriptome of Jatropha after one year of growth in both conditions using Illumina HiSeq platform. After optimized assembly, a total of 69,581 unigenes were generated. The differential gene expression (DGE) analysis revealed 3013 transcripts differentially regulated in elevated CO2 conditions. The photosynthesis regulatory genes were analysed for temporal expression patterns at four different growth phases which highlighted probable events contributing to enhanced growth and photosynthetic capacity including increased reducing power, starch synthesis and sucrose mobilization under elevated CO2. Overall, our data on physiological and transcriptomic analyses suggest an optimal resource allocation to the available and developing sink organs thereby sustaining improved photosynthetic rates during long-term growth of Jatropha under CO2 enriched environment.

Essential roles of autophagy in metabolic regulation in endosperm development during rice seed maturation

“…As osmolytes and signaling molecules, soluble sugars participate in the response and adaptation of plants to environmental stresses 59 . Under salinity stress, photosynthetic carbon assimilation is inhibited, and starch turnover as well as an accumulation of soluble sugars are induced in rice leaves 60 .…”

Cloning and Characterization of Three Sugar Metabolism Genes (LBGAE, LBGALA, and LBMS) Regulated in Response to Elevated CO2 in Goji Berry (Lycium barbarum L.)

“…Elevated atmospheric CO 2 concentration in the long-term is known to affect the photosynthesis and its components as a response to increased carbohydrate production and metabolism. Long-term exposure to elevated CO 2 can result in reduced levels of mRNAs encoding specific photosynthesis genes due to increased glucose or sucrose levels in the leaves [ 5 , 19 , 20 ]. The differential expression of the sugar metabolism genes, hexokinase and sucrose phosphate synthase, was found to play a role in exerting regulatory influence on sucrose biosynthesis to accommodate enhanced photosynthesis in Jatropha subjected to a CO 2 -enriched environment [ 5 ].…”

“…Long-term exposure to elevated CO 2 can result in reduced levels of mRNAs encoding specific photosynthesis genes due to increased glucose or sucrose levels in the leaves [ 5 , 19 , 20 ]. The differential expression of the sugar metabolism genes, hexokinase and sucrose phosphate synthase, was found to play a role in exerting regulatory influence on sucrose biosynthesis to accommodate enhanced photosynthesis in Jatropha subjected to a CO 2 -enriched environment [ 5 ]. In contrast, the variation in leaf soluble carbohydrate amount at elevated and ambient CO 2 concentrations reduced with crop development, whereas the difference in transcript levels increased [ 21 ].…”

“…Climate change has profound global consequences with direct effects on agricultural production, livestock and environment quality, and indirect influence on food security and human survival [ 4 ]. Elevated atmospheric CO 2 concentration is beneficial for photosynthesis and can directly affect the growth and development of plants [ 5 , 6 , 7 ]. While plants exposed to increased levels of CO 2 are expected to benefit from carbon fertilization, the extent of advantage depends on the plant species.…”

Molecular and Physiological Alterations in Chickpea under Elevated CO2 Concentrations

“…2019 ). Combined transcriptomics with morphophysiological studies explored the improved photosynthesis under elevated CO 2 concentrations in Jatropha ( Kumar et al. 2017 ).…”