Overexpression of the Lolium perenne L. delta1-pyrroline 5-carboxylate synthase (LpP5CS) gene results in morphological alterations and salinity tolerance in switchgrass (Panicum virgatum L.)

PLoS One. 2019 Jul 16;14(7):e0219669. doi: 10.1371/journal.pone.0219669. eCollection 2019.

Abstract

In plants, Δ1-pyrroline- 5-carboxylate synthase (P5CS) is the rate-limiting enzyme in proline biosynthesis. In this study, we introduced the LpP5CS (Lolium perenne L.) gene into switchgrass by Agrobacterium-mediated transformation. The transgenic lines (TG) were classified into two groups based on their phenotypes and proline levels. The group I lines (TG4 and TG6) had relatively high proline levels and improved biomass yield. The group II lines (TG1 and TG2) showed low proline levels, severely delayed flowering, stunted growth and reduced biomass yield. Additionally, we used RNA-seq analysis to detect the most significant molecular changes, and we analyzed differentially expressed genes, such as flowering-related and CYP450 family genes. Moreover, the biomass yield, physiological parameters, and expression levels of reactive oxygen species scavenger-related genes under salt stress all indicated that the group I plants exhibited significantly increased salt tolerance compared with that of the control plants, in contrast to the group II plants. Thus, genetic improvement of switchgrass by overexpressing LpP5CS to increase proline levels is feasible for increasing plant stress tolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agrobacterium
  • Biomass
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Plant
  • Glutamate-5-Semialdehyde Dehydrogenase / genetics
  • Glutamate-5-Semialdehyde Dehydrogenase / physiology*
  • Lolium / enzymology*
  • Lolium / genetics
  • Panicum / genetics
  • Panicum / physiology*
  • Plant Proteins / genetics
  • Plant Proteins / physiology*
  • Plants, Genetically Modified / physiology
  • Pyrroles / metabolism
  • Reactive Oxygen Species / metabolism
  • Salt Tolerance*
  • Salts
  • Sequence Analysis, RNA

Substances

  • Plant Proteins
  • Pyrroles
  • Reactive Oxygen Species
  • Salts
  • delta-1-pyrroline-5-carboxylate
  • Glutamate-5-Semialdehyde Dehydrogenase

Grants and funding

This work was supported by the National National Science Foundation of China (31672478), the Ministry of Science And Technology, China (2012AA101801), and Natural Science Foundation of Beijing (6162016). All authors received a salary from the funder (Yunwei Zhang). The funder had role in study design, data collection and analysis, decision to publish, and preparation of the manuscript.