Proteomic analysis of chickpea roots reveal differential expression of abscisic acid responsive proteins

Chickpea Peptide: A Nutraceutical Molecule Corroborating Neurodegenerative and ACE-I Inhibition

Chickpea seeds are the source of proteins in human nutrition and attribute some nutraceutical properties. Herein, we report the effects of chickpea seed bioactive peptide on albumin, insulin, lactoglobulin and lysozyme amyloid fibril formation. Employing thioflavin T (ThT) assays and circular dichroism (CD), amyloid structural binding transition was experimented to analyze the inhibition of amyloid fibril formation. The purified active peptide with a molecular mass of 934.53 Da was evaluated in vitro for its ACE-I inhibitory, antibacterial, antifungal and antidiabetic activities. Further, in vivo animal studies were carried out in wistar rats for blood pressure lowering action. In hypertensive rats, chickpea peptide decreased 131 ± 3.57 mm of Hg for systolic blood pressure and 86 ± 1.5 mm of Hg for diastolic blood pressure after 8 h intraperitoneal administration. Additionally, the peptide suppressed the fibrillation of amyloid and destabilized the preformed mature fibrils. Data emphasize efficacy of chickpea peptide vis-a-vis ACE-Inhibitory, antibacterial, antifungal, antidiabetic and anti-amyloidogenic activities, allowing us to propose this novel peptide as a suitable candidate for nutraceutical-based drugs and seems the first kind of its nature.

Plant growth promoting bacteria induce anti-quorum-sensing substances in chickpea legume seedling bioassay

Microorganisms and their hosts communicate through an array of signals. Many physiological processes regulated in quorum sensing (QS) are dependent on auto-inducers, like N-acyl-homoserine lactones (AHLs) as in numerous groups of both gram-positive and gram-negative bacteria. In vitro grown seven-day old chickpea seedlings treated with plant growth promoting bacteria (PGPRs) were used to screen the AHL mimicking and for phytochemical substances like phytohormones and secondary metabolites such as phenolics and flavonoids. Potential anti-quorum sensing (anti-QS) activity surrounding the roots on semi-solid agar lawn of Chromobacterium violaceum (ATCC12742) was observed. Crude protein (4.46-8.30 μg/mL) and methanolic extracts (100 μg/mL) of seedling gave moderate anti-QS activity against CV12742 anti QS bioassay, respectively. Crude protein and methanolic extract of Bacillus amyloliquefaciens (34.00 ± 2.23; 34.00 ± 4.33 mm) and B. subtilis A (27.00 ± 2.10; 3.29 ± 2.16 mm) treated samples showed higher zone of inhibition due to anti-QS activity. Phytohormone analysis using LC-MS for zeatin, auxin and methyl jasmonate (MeJA) indicated that phytohormones were significantly upregulated by 1909.80 ng/g FW, 669.67 ng/g FW and 244.55 ng/g FW, respectively in Pseudomonas brassicacearum treated seedlings compared to control. UHPLC of PGPR treated seedlings showed overly expressed gallic acid, protocatechuic acid, catechin, p-hydroxybenzoic acid, caffeic acid, catechol, vanillin, and ferulic acid in B. amyloliquefaciens treated seedlings compared to others. Enrichment analysis identified significant pathways related to metabolism, biosynthesis of secondary metabolites. The present study indicates that chickpea neutralizes an extensive range of functional responses to AHLs that may play important role in legume host-microbe interactions.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12298-021-01034-x.

Proteomic responses to progressive dehydration stress in leaves of chickpea seedlings

Background

Chickpea is an important food legume crop with high protein levels that is widely grown in rainfed areas prone to drought stress. Using an integrated approach, we describe the relative changes in some physiological parameters and the proteome of a drought-tolerant (MCC537, T) and drought-sensitive (MCC806, S) chickpea genotype.

Results

Under progressive dehydration stress, the T genotype relied on a higher relative leaf water content after 3 and 5 d (69.7 and 49.3%) than the S genotype (59.7 and 40.3%) to maintain photosynthetic activities and improve endurance under stress. This may have been facilitated by greater proline accumulation in the T genotype than the S genotype (14.3 and 11.1 μmol g^− 1 FW at 5 d, respectively). Moreover, the T genotype had less electrolyte leakage and lower malondialdehyde contents than the S genotype under dehydration stress, indicating greater membrane stability and thus greater dehydration tolerance. The proteomic analysis further confirmed that, in response to dehydration, the T genotype activated more proteins related to photosynthesis, stress response, protein synthesis and degradation, and gene transcription and signaling than the S genotype. Of the time-point dependent proteins, the largest difference in protein abundance occurred at 5 d, with 29 spots increasing in the T genotype and 30 spots decreasing in the S genotype. Some of the identified proteins—including RuBisCo, ATP synthase, carbonic anhydrase, psbP domain-containing protein, L-ascorbate peroxidase, 6-phosphogluconate dehydrogenase, elongation factor Tu, zinc metalloprotease FTSH 2, ribonucleoproteins and auxin-binding protein—may play a functional role in drought tolerance in chickpea.

Conclusions

This study highlights the significance of genotype- and time-specific proteins associated with dehydration stress and identifies potential resources for molecular drought tolerance improvement in chickpea.