Functional characterization of late embryogenesis abundant genes and promoters in pearl millet (Pennisetum glaucum L.) for abiotic stress tolerance

Abstract

Late embryogenesis abundant (LEA) genes display distinct functions in response to abiotic stresses in plants. In pearl millet (Pennisetum glaucum L.), a total of 21 PgLEA genes were identified and classified into six groups including LEA1, LEA2, LEA3, LEA5, LEA7, and dehydrins (DHN). Open reading frames (ORFs) of PgLEAs range from 291 bp (PgLEA1-1) to 945 bp (PgLEA2-11) and distributed randomly among the seven chromosomes. Phylogenetic analysis revealed that all PgLEA proteins are closely related to sorghum LEA proteins. The PgLEAs were found to be expressed differentially under high progressive vapor pressure deficit (VPD), PgLEA7 was significantly expressed under high VPD and was selected for functional validation. In silico analysis of the PgLEA promoter regions revealed abiotic stress-specific cis-acting elements such as ABRE, CCAAT, MYBS, and LTRE. Based on the type of motifs, PgLEAPC promoter (758 bp), its deletion 1 (PgLpd1, 349 bp) and deletion 2 (PgLpd2, 125 bp) were cloned into the plant expression vector pMDC164 having the promoter-less uidA gene. All the three plant expression vectors were introduced into tobacco through Agrobacterium tumefaciens-mediated transformation to obtain T 1 and T 2 generations of transgenic plants. Based on expression of the uidA gene, tissue-specific expression was observed in mature stems, roots and seedlings of PgLEAPC and PgLpd1 carrying transgenics only. While the transgenic PgLEAPC plants displayed significantly higher uidA expression in the stem and root tissues under salt, drought, heat, and cold stresses, very low or no expression was observed in PgLpd1 and PgLpd2 transgenics under the tested stress conditions. The results of this study indicate that the complete promoter of PgLEAPC plays a role in developing abiotic stress tolerance in plants. 1 | INTRODUCTION Higher plants display a plethora of physiological, biochemical, and molecular changes in response to harsh environmental conditions (Soltis & Soltis 2003). As a response to water deficit, plants accumulate higher levels of soluble sugars and other compatible solutes like proline, trehalose, glycine betaine and mannitol These molecules help in osmotic adjustment, to stabilize proteins and enzymes, and mitigate the damages caused by the reactive oxygen species

Characterization of the Fatty Acyl-CoA Reductase (FAR) Gene Family and Its Response to Abiotic Stress in Rice (Oryza sativa L.)

“…Among these, OsFAR2 was significantly induced under low temperature, salt, drought, and ABA treatments. Previous research revealed that CREs in the promoter region can be bound by regulatory factors, leading to the induction of their expression under abiotic stress [52]. Our analysis found CREs such as ABREs, MBS, and STREs in the OsFAR2 gene promoter, indicating its ability to induce OsFAR2 expression under abiotic stress.…”

In Silico Characterisation of the Late Embryogenesis Abundant (LEA) Protein Families and Their Role in Desiccation Tolerance in Ramonda serbica Panc

“…A hallmark of desiccation tolerance is the accumulation of protective late embryogenesis abundant proteins (LEAPs), which may stabilise the correct structure of proteins and membranes during cellular dehydration [ 3 , 12 , 13 ]. In-depth studies and characterisations of LEA protein families have been carried out in various plants such as Arabidopsis [ 14 ], upland cotton [ 15 ], potato [ 16 ], common wheat [ 17 ], tea plant [ 18 ], rice [ 19 ], pearl millet [ 20 ], Sorghum bicolor [ 21 ], legumes [ 22 ], and desert plant Cleistogenes songorica [ 23 ]. An identification and detailed structural and functional analysis of LEA proteins of resurrection plant species R. serbica has not been done yet.…”

The Caucasian Clover Gene TaMYC2 Responds to Abiotic Stress and Improves Tolerance by Increasing the Activity of Antioxidant Enzymes

“…Lastly, the expression of ROS scavenging-related and stress-responsive genes was measured in transgenic tobacco under drought and cold stress. Studies have shown that these genes or their homologous genes play roles in ROS scavenging- and stress-related responses [ 51 , 52 , 53 , 54 ]. Overexpression of TaMYC2 could induce the expression of ROS scavenging-related and stress-responsive genes to a certain extent.…”