Physiological and transcriptome analysis of Poa pratensis var. anceps cv. Qinghai in response to cold stress

Abstract

Background Low temperature limits the growth and geographical distribution of plants. Poa pratensis is a cool-season turfgrass mainly grown in urban areas. However, low winter temperature or cold events in spring and autumn may cause P.pratensis mortality, affecting the appearance of lawns. P.pratensis var. anceps cv. Qinghai (PQ) is widely distributed in the Qinghai-Tibet Plateau above 3000 m. PQ has greater cold resistance than the commercially cultivated P.pratensis varieties. However, existing studies on the response mechanism of PQ to low temperatures have mainly focused on physiological and biochemical perspectives, while changes in the PQ transcriptome during the response to cold stress have not been reported. Results To investigate the molecular mechanism of the PQ cold response and identify genes to improve the low-temperature resistance of P.pratensis, we analyzed and compared the transcriptomes of PQ and the cold-sensitive P.pratensis cv. ‘Baron’ (PB) under cold stress using RNA sequencing. We identified 4878 and 1871 differentially expressed genes (DEGs) between the treatment vs control comparison of PQ and PB, respectively, with 4494 DEGs specific to PQ. Based on the DEGs, important Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as “starch and sucrose metabolism”, “protein processing in endoplasmic reticulum”, “phenylalanine metabolism” and “glycolysis/gluconeogenesis” were significantly enriched in PQ, and “starch and sucrose metabolism”, “phenylpropanoid biosynthesis”, “galactose metabolism” and “glutathione metabolism” were significantly enriched in PB. In addition, the “glycolysis” and “citrate cycle (TCA cycle)” pathways were identified as involved in cold resistance of P.pratensis. Conclusions As we know, this is the first study to explore the transcriptome of P.pratensis var. anceps cv. Qinghai. Our study not noly provides important insights into the molecular mechanisms of P.pratensis var. anceps cv. Qinghai responds to cold stress, but also systematically reveals the changes of key genes and products of glycolysis and TCA cycle in response to cold stress, which is conductive to the breeding of cold-resistant P.pratensis genotype.

Transcriptome analysis and differential gene expression profiling of wucai (Brassica campestris L.) in response to cold stress

“…Starch is hydrolyzed/decomposed into maltose/dextrin by alpha amylase 3 (AMY3) and BAM2 and is then hydrolyzed into glucose by 4-alpha-glucanotransferase (DPE2). It was reported that sucrose and starch metabolism was significantly enriched and the content of soluble sugar was significantly increased after cold stress in Poa pratensis with different cold tolerance [41]. Poa pratensis is a cold tolerant species, and this result was consistent with ours.…”

Testing the chilling‐ before drought‐tolerance hypothesis in Pooideae grasses

“…However, the majority of DEG functional categories are tribe‐specific, and have not been previously characterized as stress responsive outside Pooideae. These 67 tribe‐specific genes are primarily annotated as being involved in metabolism, and as such represent good candidates for engineering chilling–drought cross‐tolerance in temperate grass crops (Dong et al, 2020; Priest et al, 2014). Characterization of drought responsive genes alone also revealed genes that are known to be involved in oxidative and salt stress tolerance pathways outside of Pooideae (Abbasi‐Vineh et al, 2021; Chen, Jiang, et al, 2012; Chen, Lv, et al, 2012; Liu et al, 2014; Tasseva et al, 2004; Wang et al, 2017).…”

“…However, the majority of DEG functional categories are tribespecific, and have not been previously characterized as stress responsive outside Pooideae. These 67 tribe-specific genes are primarily annotated as being involved in metabolism, and as such represent good candidates for engineering chilling-drought cross-tolerance in temperate grass crops (Dong et al, 2020;Priest et al, 2014).…”

Full length transcriptome sequencing and differential expression gene analysis of Hybrid Larch under PEG simulated drought stress

“…Glucose metabolism is involved in many biological processes, and most of the products in metabolic processes are important osmoregulatory factors, playing an important role in maintaining the structure and pressure stability of water-soluble proteins in cells[ 20] [21] . A total of 118 DEGs involved in glucose metabolism were identi ed in this study, among which 44 genes were up-regulated and 74 genes were down-regulated.…”