Overexpression of a novel cold‐responsive transcript factor LcFIN1 from sheepgrass enhances tolerance to low temperature stress in transgenic plants

Abstract

SummaryAs a perennial forage crop broadly distributed in eastern Eurasia, sheepgrass (Leymus chinensis (Trin.) Tzvel) is highly tolerant to low-temperature stress. Previous report indicates that sheepgrass is able to endure as low as À47.5°C,allowing it to survive through the cold winter season. However, due to the lack of sufficient studies, the underlying mechanism towards the extraordinary low-temperature tolerance is unclear. Although the transcription profiling has provided insight into the transcriptome response to cold stress, more detailed studies are required to dissect the molecular mechanism regarding the excellent abiotic stress tolerance. In this work, we report a novel transcript factor LcFIN1 (L. chinensis freezinginduced 1) from sheepgrass. LcFIN1 showed no homology with other known genes and was rapidly and highly induced by cold stress, suggesting that LcFIN1 participates in the early response to cold stress. Consistently, ectopic expression of LcFIN1 significantly increased cold stress tolerance in the transgenic plants, as indicated by the higher survival rate, fresh weight and other stress-related indexes after a freezing treatment. Transcriptome analysis showed that numerous stress-related genes were differentially expressed in LcFIN1-overexpressing plants, suggesting that LcFIN1 may enhance plant abiotic stress tolerance by transcriptional regulation. Electrophoretic mobility shift assays and CHIP-qPCR showed that LcCBF1 can bind to the CRT/DRE cis-element located in the promoter region of LcFIN1, suggesting that LcFIN1 is directly regulated by LcCBF1. Taken together, our results suggest that LcFIN1 positively regulates plant adaptation response to cold stress and is a promising candidate gene to improve crop cold tolerance.

Lignification of Sheepgrass Internodes at Different Developmental Stages and Associated Alteration of Cell Wall Saccharification Efficiency

“…SYBR Green (Takara, Dalian, China) was used as the reporter dye. The cycle thresholds were determined using the LightCycler ® 480 Real-time PCR System (Roche Applied Science, Upper Bavaria, Germany), and the data were normalized using the level of sheepgrass ACTIN transcripts (Gao et al, 2016). …”

“…Recent studies on sheepgrass have focused on how to utilize this type of lignocellulosic feedstock and its gene resource (Wang et al, 2009; Chen et al, 2015; Gao et al, 2016; Zhao et al, 2016). In our work, sheepgrass internodes at different developmental stages were collected for investigating the effects of lignification on cell wall digestibility.…”

De novo transcriptome sequencing and gene expression profiling of Elymus nutans under cold stress

“…Five seedlings were planted in each pot and grown for 28 d in a growth chamber at a 25/25 °C day/night temperature, 14 h/10 h (day/night) photoperiod with a photon flux density of 350 μmol m −2 s −1 and a constant humidity of 70 %. Cold stress treatment was performed on these samples by transferring 28-d-old pot-growing plants (three-leaf stage) to a growth chamber set to 4 °C under the photoperiodic conditions described above [45]. The 28-d-old seedlings were exposed to cold stress at 09: 00 h, and leaf were harvested at 0 h (control), 3, 24 h, and 5 d after cold treatments, and then quickly frozen in liquid nitrogen and stored at –80 °C.…”

LcFIN2, a novel chloroplast protein gene from sheepgrass, enhances tolerance to low temperature in Arabidopsis and rice

“…The accumulation of ROS causes an increase in lipid peroxidases and causes an inhibition of plant growth (Nahar et al ). Therefore, to alleviate the oxidative damage induced by ROS, plants have enhanced proline, soluble sugars and enzymatic antioxidants such as superoxide dismutase (SOD), peroxidase and catalase (Kong et al , Erdal et al , Gao et al ). In addition, ROS may cause oxidative damage to chloroplasts by reacting with biomolecules such as nucleic acids, proteins and lipids (Yokotani et al ).…”