Molecular insights into the salt stress response of Pearl millet (Pennisetum glaucum): Pathways, differentially expressed genes and transcription factors

Abstract

IntroductionPearl millet (Pennisetum glaucum) plays a crucial role as a cereal crop in arid and semi‐arid regions, where it confronts the formidable challenge of salt stress.Materials and MethodsTo unravel the underlying molecular mechanisms that underpin its salt stress resilience, we subjected 14‐day‐old seedlings to three distinct groups: Control, 75 mM NaCl and 150 mM NaCl. These pots received daily irrigation with their respective treatment solutions for a duration of 7 days. Following this week‐long treatment, we measured plant chlorophyll content, as well as the fresh and dry weights of shoots and roots. It became evident that the saline treatment, particularly in the 150 mM NaCl group, had a more pronounced impact on both weight and chlorophyll content in comparison to the control group, surpassing the effects observed in the 75 mM NaCl group. Subsequently, we conducted RNA sequence analysis on the leaves of Pearl millet from both the control and 150 mM NaCl‐treated groups.ResultsThe results revealed that 27.6% of Pennisetum glaucum genes exhibited differential expression, with 3246 genes being upregulated and 7408 genes downregulated when compared to the control group. Principal component analysis underscored distinct variations in gene expression patterns between the control and salt‐stressed groups. Pathway analysis sheds light on the upregulated differentially expressed genes (DEGs), highlighting their involvement in crucial pathways such as phytyl‐PP biosynthesis, lysine degradation, glutamate biosynthesis, nitrate assimilation and DLO biosynthesis. Conversely, the downregulated DEGs were associated with pathways like coumarins biosynthesis, pinobanksin biosynthesis, UDP‐ d‐glucuronate biosynthesis and cholesterol biosynthesis, among others. Furthermore, our transcription factor analysis unveiled specific families associated with the salt stress response, including bHLH, ERF, NAC, WRKY, bZIP, MYB and HD‐ZIP.ConclusionsThese findings represent a significant advancement in our comprehension of Pearl millet's capacity to withstand salt stress and provide potential targets for the development of salt‐resistant crops, contributing to the advancement of sustainable agriculture in regions affected by salinity.

Cryptic Resilience: Decoding Molecular Networks in Pearl Millet for Enhanced Heat Stress

“…For instance, the application of melatonin has been shown to reduce cadmium toxicity in pearl millet, fostering development and enhancing antioxidant defense, as demonstrated by Awan et al [10]. Additionally, our previous study [11] delves into the pearl millet (Pennisetum glaucum) response to salt stress, a significant concern in arid and semi-arid environments. In this experiment, 14-day-old seedlings were subjected to seven days of daily irrigation before being categorized into control, 75 mM NaCl, and 150 mM NaCl.…”

“…As previously mentioned in our earlier investigation [11], the seeds utilized in the current study belong to the classification of pearl millet [Pennisetum] glaucum subsp. monodii.…”

“…RNA sequencing of leaves unveiled 3246 upregulated and 7408 downregulated genes, accounting for 27.6% of differentially expressed genes. In the investigation outlined in this study [11], pathway analysis uncovered associations between downregulated genes and the synthesis of coumarin and cholesterol. Conversely, upregulated genes were linked to crucial processes such as lysine degradation and phytyl-PP biosynthesis.…”

Abiotic stress tolerance in pearl millet: Unraveling molecular mechanisms via transcriptomics

“…Subsequently, seedlings were transplanted into a growth medium comprising equal parts vermiculite and soil after 48 h. Each pot, measuring 6 × 17 in, received 20 ml of distilled water for irrigation within a conservatory set at 25°C. In accordance with our prior research, 8,9 the experimental design included two abiotic treatment options (150 Mmol salt stress and 50°C thermal stress).…”

“…Unraveling stress tolerance mechanisms offers great potential for sustainable agriculture and environmental protection. 8 Leveraging plant resilience is crucial to ensure nutritious food for the world's growing population.…”