BZR proteins: identification, evolutionary and expression analysis under various exogenous growth regulators in plants.

BACKGROUNDS: The BRASSINAZOLE-RESISTANT (BZR) family of transcription factors affects a variety of developmental and physiological processes and plays a key role in multiple stress-resistance functions in plants. However, the evolutionary relationship and individual expression patterns of the BZR genes are unknown in various crop plants. METHODS AND RESULTS: In this study, we performed a genome-wide analysis of the BZR genes family in wheat and rice. Here, we found a total of 16 and 6 proteins containing the BZR domain in wheat and rice respectively. The phylogenetic analysis divided the identified BZR proteins from several plants into five subfamilies. The intron/exon structural patterns and conserved motifs distribution revealed that BZR proteins exhibite high specificities in each subfamily. Moreover, the co-expression and protein-protein interaction analysis suggested that BZR proteins may interact/co-expressed with several other proteins to perform various functions in plants. The presence of different stresses, hormones and light-responsive cis-elements in promoter regions of BZR genes imply its diverse functions in plants. The expression patterns indicated that many BZR genes regulate organ development and differentiation. BZR genes significantly respond to exogenous application of brassinosteroids, melatonin and abiotic stresses, demonstrating its key role in various developmental and physiological processes. CONCLUSION: The present study establishes the foundation for future functional genomics studies of BZR genes through reverse genetics and to further explore the potential of BZR genes in mitigating the stress tolerance in crop plants.

Transcriptome Analysis Reveals Potential Mechanism in Storage Protein Trafficking within Developing Grains of Common Wheat.

Gluten proteins are the major storage protein fraction in the mature wheat grain. They are restricted to the starchy endosperm, which defines the viscoelastic properties of wheat dough. The synthesis of these storage proteins is controlled by the endoplasmic reticulum (ER) and is directed into the vacuole via the Golgi apparatus. In the present study, transcriptome analysis was used to explore the potential mechanism within critical stages of grain development of wheat cultivar "Shaannong 33" and its sister line used as the control (CK). Samples were collected at 10 DPA (days after anthesis), 14 DPA, 20 DPA, and 30 DPA for transcriptomic analysis. The comparative transcriptome analysis identified that a total of 18,875 genes were differentially expressed genes (DEGs) between grains of four groups "T10 vs. CK10, T14 vs. CK14, T20 vs. CK20, and T30 vs. CK30", including 2824 up-regulated and 5423 down-regulated genes in T30 vs. CK30. Further, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment highlighted the maximum number of genes regulating protein processing in the endoplasmic reticulum (ER) during grain enlargement stages (10-20 DPA). In addition, KEGG database analysis reported 1362 and 788 DEGs involved in translation, ribosomal structure, biogenesis, flavonoid biosynthesis pathway and intracellular trafficking, secretion, and vesicular transport through protein processing within ER pathway (ko04141). Notably, consistent with the higher expression of intercellular storage protein trafficking genes at the initial 10 DPA, there was relatively low expression at later stages. Expression levels of nine randomly selected genes were verified by qRT-PCR, which were consistent with the transcriptome data. These data suggested that the initial stages of "cell division" played a significant role in protein quality control within the ER, thus maintaining the protein quality characteristics at grain maturity. Furthermore, our data suggested that the protein synthesis, folding, and trafficking pathways directed by a different number of genes during the grain enlargement stage contributed to the observed high-quality characteristics of gluten protein in Shaannong 33 (Triticum aestivum L.).

Update on the Basic Understanding of Fusarium graminearum Virulence Factors in Common Wheat Research.

Wheat is one of the most important food crops, both in China and worldwide. Wheat production is facing extreme stresses posed by different diseases, including Fusarium head blight (FHB), which has recently become an increasingly serious concerns. FHB is one of the most significant and destructive diseases affecting wheat crops all over the world. Recent advancements in genomic tools provide a new avenue for the study of virulence factors in relation to the host plants. The current review focuses on recent progress in the study of different strains of Fusarium infection. The presence of genome-wide repeat-induced point (RIP) mutations causes genomic mutations, eventually leading to host plant susceptibility against Fusarium invasion. Furthermore, effector proteins disrupt the host plant resistance mechanism. In this study, we proposed systematic modification of the host genome using modern biological tools to facilitate plant resistance against foreign invasion. We also suggested a number of scientific strategies, such as gene cloning, developing more powerful functional markers, and using haplotype marker-assisted selection, to further improve FHB resistance and associated breeding methods.

Genome-wide identification and expression analysis of CPP-like gene family in Triticum aestivum L. under different hormone and stress conditions.

The CPP-like plant-specific transcription factor has a prominent role in plant development and growth through cell division and differential activities. However, little information is available about the CPP gene family in Triticum aestivum L. Herein, we identified 37 and 11 CPP genes in the wheat and rice genome databases, respectively. The phylogeny of the CPP protein-like family members was further divided into five subfamilies based on structural similarities and phenotypic functional diversities. The in silico expression analysis showed that CPP genes are highly expressed in some tissues, such as shoot apex, shoot, leaf, leaf sheath, and microspore. Furthermore, the qRT-PCR found higher expression for TaCPP gene family members in leaf, leaf blade, young spike, mature spike, and differential expression patterns under abiotic stresses, including heat, drought, salt, and hormonal treatment, such as indole acetic acid and 1-aminocyclopropane-1 carboxylic acid. We found that CPP gene family members are mostly located in the nucleus after infiltrating the CPP5-1B-GFP and TaCPP11-3B-GFP into tobacco leaves. The overexpression of the TaCPP5-1D gene revealed that the CPP gene positively regulates the germanium, shoot, and root activities in Arabidopsis. The TaCPP5-1D-overexpressed plants showed less anti-oxidative sensitivity under drought stress conditions. These results demonstrated that TaCPP5-1D protein has a crucial contribution by interacting with TaCPP11-3B protein in maintaining stress homeostasis under the natural and unfavorable environmental conditions for growth, development, and stress resistance activities. Therefore, this study could be used as pioneer knowledge to further investigate the function of CPP genes in plant growth and development.

Melatonin Suppressed the Heat Stress-Induced Damage in Wheat Seedlings by Modulating the Antioxidant Machinery.

Melatonin (N-acetyl-5-methoxytryptamine) is a pleiotropic signaling molecule that plays a crucial role in the regulation of various environmental stresses, including heat stress (HS). In this study, a 100 µM melatonin (MT) pretreatment followed by exposure to heat stress for different time periods was found to efficiently reduce oxidative stress by preventing the over-accumulation of hydrogen peroxide (H2O2), lowering the lipid peroxidation content (malondialdehyde (MDA) content), and increasing proline (Pro) biosynthesis. Moreover, the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), were increased substantially in MT-pretreated wheat seedlings. The presence of MT significantly improved the heat tolerance of wheat seedlings by modulating their antioxidant defense system, activating the ascorbate-glutathione (AsA-GSH) cycle comprising ascorbate peroxidase (APX), and increasing glutathione reductase (GR) activities. It also held the photosynthetic machinery stable by increasing the chlorophyll content. Enhancement in the endogenous MT contents was also observed in the MT+HS-treated plants. Furthermore, the expression of reactive oxygen species (ROS)-related genes TaSOD, TaPOD, and TaCAT, and anti-stress responsive genes, such as TaMYB80, TaWRKY26, and TaWRKY39, was also induced in MT-treated seedlings. Due to these notable changes, an improvement in stress resistance was observed in MT-treated seedlings compared with control. Taken together, our findings suggest that MT can play a key role in boosting the stress tolerance of plants by modulating the antioxidant defense system and regulating the transcription of stress-responsive genes.