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Biomedical subjects

Weiqiang Li

Publications and source records attributed to Weiqiang Li.

5 recordsLinked to original sources

Discovery of specific rhizosphere bacteria Rhodanobacter involved in KAI2-mediated drought tolerance in Arabidopsis.

The KARRIKIN INSENSITIVE 2 (KAI2) receptor has been reported to contribute to drought tolerance in Arabidopsis. However, the extent to which KAI2's function in drought tolerance depends on soil microbiota remains unclear. This study demonstrates that the rhizosphere microbiome is indispensable for KAI2-mediated drought tolerance. We isolated specific Rhodanobacter sp. and confirmed its role in enhancing drought tolerance in Arabidopsis. Notably, Rhodanobacter sp. was found to specifically secrete the key isoflavone daidzin. We found that daidzin had a similar function with KAI2 agonist, desmethyl-type germinone, and induced interaction between KAI2 and SUPRESSOR OF MORE AXILLARY GROWTH 2 1. Moreover, the exogenous application of daidzin enhanced drought tolerance by modulating the expression of karrikin response and drought-related genes, in a KAI2-dependent manner. Our findings suggest that the rhizosphere microbiome plays a crucial role in facilitating KAI2-mediated drought tolerance in Arabidopsis, with Rhodanobacter sp. contributing through the secretion of daidzin.

Arabidopsis

From activation to desensitization: How ABA balances plant growth and abiotic stress response?

Abscisic acid (ABA) signaling is a central regulator of plant adaptation to abiotic stress, dynamically coordinating stress responses with growth and development. Rapid activation of ABA signaling promotes plant survival during the early stages of stress, whereas prolonged stress requires timely attenuation of the pathway to restore growth and prevent excessive stress responses. Recent studies have uncovered diverse mechanisms underlying ABA desensitization, including regulation of SnRK2 kinases, phytohormone crosstalk, nutrient signaling, protein trafficking, post-translational modifications, and feedback regulatory networks. Together, these interconnected mechanisms enable plants to fine-tune ABA signaling in response to developmental and environmental cues. In this review, we summarize recent advances in understanding the molecular mechanisms that attenuate ABA signaling and restore the balance between growth and stress adaptation during prolonged stress. We also highlight outstanding questions and discuss strategies for engineering ABA signaling dynamics to improve crop resilience, productivity, and adaptation to increasingly variable environments.

Abscisic Acid

Small nucleolar RNA HIDDEN TREASURE 2 reduces drought tolerance via multiple pathways in Arabidopsis.

Small nucleolar RNAs (snoRNAs) contribute to ribosome biogenesis and modulate various aspects of plant growth and development. Given that osmotic stress downregulates numerous genes associated with ribosome biogenesis in roots, we hypothesize that snoRNAs might function in modulating plant responses to osmotic and drought stresses. To prove this hypothesis, we assessed the role of a C/D-box snoRNA, namely the HIDDEN TREASURE 2 (HID2), in Arabidopsis thaliana responses to drought using both loss-of-function and overexpression approaches. Under drought conditions, the Arabidopsis hid2 mutant displayed a significantly higher survival rate than both wild-type (WT) and HID2-complemented plants, while HID2-overexpressing plants showed a lower survival rate than WT. A series of physiological assays indicated that the hid2 mutant maintained a slower rate of water loss and more intact cell membranes than WT plants under drought, which supported their drought-tolerant phenotype. Comparative leaf transcriptome and proteome analyses revealed that processes related to wax biosynthesis, senescence, and anthocyanin accumulation were differentially regulated between hid2 and WT plants under water-deficit conditions. Consistently, the hid2 mutant accumulated higher amounts of wax and anthocyanins and exhibited delayed leaf senescence relative to WT plants under drought. Additionally, the hid2 mutant showed improved ability to increase sensitivity to abscisic acid (ABA), scavenge reactive oxygen species (ROS), and extended root hairs. Overall, these findings demonstrate HID2's role as a negative modulator in Arabidopsis drought tolerance by negatively affecting cell membrane stability, wax and anthocyanin biosynthesis, senescence, ROS-scavenging capacity, ABA responsiveness, and root hair formation.

Arabidopsis

The small nucleolar RNA NON-CODING RNA 1 negatively regulates drought tolerance in Arabidopsis thaliana.

Small nucleolar RNAs (snoRNAs) function in ribosome biogenesis, and many ribosome biogenesis-related genes were downregulated by osmotic stress, implying a negative role of snoRNAs in drought tolerance. A snoRNA, namely, the NON-CODING RNA 1 (NCR1) was studied for its roles in drought tolerance in Arabidopsis. In comparison with wild-type (WT) plants, the loss-of-function ncr1 mutant plants showed enhanced drought tolerance, which was restored in the NCR1-complemented plants, whereas the NCR1-overexpressing plants revealed a drought-sensitive phenotype. Physiological analyses revealed that the ncr1 plants had a higher leaf surface temperature, lower water loss rates, and improved cell membrane integrity compared with WT. Comparative leaf transcriptomics and proteomics suggested that wax biosynthesis, anthocyanin metabolism, and leaf senescence processes are regulated by NCR1 under both normal and water-deficit conditions. Under drought, an increase in wax and anthocyanin accumulations and a delay in leaf senescence in ncr1 plants, when compared with WT, supported the transcriptome and proteomics data. Additionally, the ncr1 plants exhibited higher abscisic acid (ABA) sensitivity and longer root hairs than WT. Collectively, our results suggest that NCR1 negatively regulates drought tolerance through modification of wax biosynthesis, anthocyanin accumulation, leaf senescence, cell membrane integrity, ABA responses, and root hair development.

Arabidopsis

Mechanistic roles of GmSWEET10a/b and GmSUT1 in the oil-protein balance in soybean mature seeds at transcriptional and metabolic levels.

Previous investigations indicated that the soybean (Glycine max) SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER10a/b (GmSWEET10a/b) genes promote oil accumulation, while inhibiting protein accumulation in seeds. To clarify the mechanisms modulated by GmSWEET10a/b in mediating the oil and protein accumulations in soybean seeds, an integrated comparative multiomics was conducted using the double gmsweet10a,b mutant and wild-type (WT) embryos. Spatial metabolomic analysis revealed that gmsweet10a,b embryos were surrounded by a sugar-reduced seed coat and experienced a sugar-starvation state in embryonic tissues in vivo. The decreased sugar content in the gmsweet10a,b embryos reduced the availability of carbon skeletons required for oil synthesis and was associated with decreased expression levels of genes involved in sucrose metabolism, fatty acid biosynthesis, and triacylglycerol assembly. Meanwhile, the expression of genes encoding storage protein was induced in gmsweet10a,b embryos, when compared with WT. These changes resulted in decreased oil content and increased protein content in gmsweet10a,b embryos versus WT. In vitro sugar-starvation assay also supported the suppression of fatty acid biosynthesis and the enhanced storage protein accumulation in developmental embryo under sugar-starved conditions. Furthermore, the knockout of SUCROSE TRANSPORTER 1 (GmSUT1), which was upregulated in gmsweet10a,b embryos, significantly decreased the sugar level, resulting in lower oil content but higher protein content in gmsut1 embryos than WT ones. Our findings provided a mechanistic understanding of the modulation of sugar transport between seed coat to embryo by both GmSWEET10a/b and GmSUT1, which plays a pivotal role in balancing oil and protein accumulations in soybean mature seeds.

Seeds