Comparative Physiology and Transcriptome Analysis of Young Spikes in Response to Late Spring Coldness in Wheat (Triticum aestivum L.)

Abstract

Late spring coldness (LSC) is critical for wheat growth and development in the Huang-Huai valleys of China. However, little is known about the molecular mechanisms for young spikes responding to low temperature (LT) stress during anther connective tissue formation phase (ACFP). To elucidate the molecular mechanisms associated with low temperature, we performed a comparative transcriptome analysis of wheat cultivars Xinmai26 (XM26: cold-sensitive) and Yannong19 (YN19: cold-tolerant) using RNA-seq data. Over 4000 differently expressed genes (DEGs) were identified under low temperature conditions (T1: 4°C) and freezing conditions (T2: −4°C) compared with control (CK: 16°C). The number of DEGs associated with two cultivars at two low temperature treatments (T1: 4°C and T2: −4°C) were 834, 1,353, 231, and 1,882 in four comparison groups (Xinmai26-CK vs. Xinmai26-T1, Xinmai26-CK vs. Xinmai26-T2, Yannong19-CK vs. Yannong19-T1, and Yannong19-CK vs. Yannong19-T2), respectively. Furthermore, to validate the accuracy of RNA-seq, 16 DEGs were analyzed using quantitative real-time RT-PCR. Several transcriptome changes were observed through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway functional enrichment analysis in plant hormone signal transduction, circadian rhythm-plant, and starch and sucrose metabolism under low temperature. In addition, 126 transcription factors (TFs), including AP2-ERF, bHLH, WRKY, MYB, HSF, and members of the bZIP family, were considered as cold-responsive. It is the first study to investigate DEGs associated with low temperature stress at the transcriptome level in two wheat cultivars with different cold resistance capacities. Most likely, the variations in transcription factors (TFs) regulation, and starch and sucrose metabolism contribute to different cold resistance capacities in the two cultivars. Further, physiological activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) enzymes, malondialdehyde (MDA), soluble sugar (SS), and sucrose contents were evaluated to investigate the negative impacts of low temperature in both cultivars. These findings provide new insight into the molecular mechanisms of plant responses to low temperature and potential candidate genes that required for improving wheat’s capacity to withstand low temperature stress.

Transcriptome analysis of the winter wheat Dn1 in response to cold stress

“…The accumulation of sucrose and soluble sugar in plants under cold stress plays an important role in osmoprotection, maintenance of membrane stability, protein stability, carbohydrate homeostasis and intracellular expansion [ 68 – 70 ]. Jiang et al [ 71 ] found that the expression of eight genes encoding sucrose synthase and two genes encoding beta-amylases was significantly upregulated in the transcriptome of cold-tolerant wheat, the sucrose content and soluble sugar content were also upregulated in cold-tolerant wheat under cold stress. Wang et al [ 72 ] also found that the expression of SUS6 , SPS1 , AMY3 and BAM2 was significantly upregulated in the transcriptome of cold-tolerant Brassica campestris L. and the soluble sugar content was also upregulated under cold stress, meanwhile starch synthesis was not inhibited.…”

Optimized Phosphorus Application Alleviated Adverse Effects of Short-Term Low-Temperature Stress in Winter Wheat by Enhancing Photosynthesis and Improved Accumulation and Partitioning of Dry Matter

“…Here, low-temperature stress causes flower abortion, pollen and ovule sterility, disrupts fertilization and affects seed filling, resulting in poor seed setting and consequently lowered grain yield [56]. Our study showed that the chilling stress (T1) at the anther differentiation period did not significantly reduce SNPP in the two cultivars but could substantially reduce the GNPP in the sensitive cultivar XM26.…”

“…The yield reduction rate of the cold-sensitive cultivar was more than 90% at −2 • C for 24 h [5]. This was due to the late development of upper spikelets, less accumulation of nutrients and osmotic adjustment substances [10,56]. Low-temperature stress had different effects on yield and its components in different growth stages of wheat.…”

Proteomic and Phosphoproteomic Analyses Reveal a Complex Network Regulating Pollen Abortion and Potential Candidate Proteins in TCMS Wheat

“…ROS is an important product of oxidative stress in plant cells and a key element of programmed cell death. Under normal circumstances, the ROS system is in a state of dynamic equilibrium [ 28 ]. ROS-related indicators in anthers were analyzed to evaluate whether YS3038-A infertility is mediated by the ROS system.…”

“…These results indicated that the accumulation rate of ROS in YS3038-A was higher than the scavenging rate, and the dynamic balance between the accumulation and scavenging of ROS was abnormal. Studies have shown that excessive ROS accumulation can lead to abnormal development of anther apoptosis and ultimately lead to male sterility [ 28 , 29 , 30 ].…”