Sound as a stimulus in associative learning for heat stress in Arabidopsis

Vegetal memory through the lens of transcriptomic changes - recent progress and future practical prospects for exploiting plant transcriptional memory

Plant memory plays an important role in the efficient and rapid acclimation to a swiftly changing environment. In addition, since plant memory can be inherited, it is also of adaptive and evolutionary importance. The ability of a plant to store, retain, retrieve and delete information on acquired experience is based on cellular, biochemical and molecular networks in the plants. This review offers an up-to-date overview on the formation, types, checkpoints of plant memory based on our current knowledge and focusing on its transcriptional aspects, the transcriptional memory. Roles of long and small non-coding RNAs are summarized in the regulation, formation and the cooperation between the different layers of the plant memory, i.e. in the establishment of epigenetic changes associated with memory formation in plants. The RNA interference mechanisms at the RNA and DNA level and the interplays between them are also presented. Furthermore, this review gives an insight of how exploitation of plant transcriptional memory may provide new opportunities for elaborating promising cost-efficient, and effective strategies to cope with the ever-changing environmental perturbations, caused by climate change. The potentials of plant memory-based methods, such as crop priming, cross acclimatization, memory modification by miRNAs and associative use of plant memory, in the future's agriculture are also discussed.

Plants detect and respond to sounds

Specific sound patterns can affect plant development. Plants are responsive to environmental stimuli such as sound. However, little is known about their sensory apparatus, mechanisms, and signaling pathways triggered by these stimuli. Thus, it is important to understand the effect of sounds on plants and their technological potential. This review addresses the effects of sounds on plants, the sensory elements inherent to sound detection by the cell, as well as the triggering of signaling pathways that culminate in plant responses. The importance of sound standardization for the study of phytoacoustics is demonstrated. Studies on the sounds emitted or reflected by plants, acoustic stress in plants, and recognition of some sound patterns by plants are also explored.

Comparative transcriptome analyses revealed key genes involved in high amylopectin biosynthesis in wheat

High amylopectin starch is an important modified starch for food processing industries. Despite a thorough understanding of starch biosynthesis pathway, the regulatory mechanism responsible for amylopectin biosynthesis is not well explored. The present study utilized transcriptome sequencing approach to understand the molecular basis of high amylopectin content in three high amylopectin mutant wheat lines ('TAC 6', 'TAC 358', and 'TAC 846') along with parent variety 'C 306'. Differential scanning calorimetry (DSC) of high amylopectin starch identified a high thermal transition temperature and scanning electron microscopy (SEM) revealed more spherical starch granules in mutant lines compared to parent variety. A set of 4455 differentially expressed genes (DEGs) were identified at two-fold compared to the parent variety in high amylopectin wheat mutants. At ten-fold, 279 genes, including two starch branching genes (SBEIIa and SBEIIb), were up-regulated and only 30 genes, including the starch debranching enzyme (DBE), were down-regulated. Among the genes, different isoforms of sucrose non-fermenting-1-related protein kinase-1 (TaSnRK1α2-3B and TaSnRK1α2-3D) and its regulatory subunit, sucrose non-fermenting-4 (SNF-4-2A, SNF-4-2B, and SNF-4-5D), were found to be highly up-regulated. Further, expression of the DEGs related to starch biosynthesis pathway and TaSnRK1α2 and SNF-4 was performed using qRT-PCR. High expression of TaSnRK1α2, SNF-4, and SBEII isoforms suggests their probable role in high amylopectin starch biosynthesis in grain endosperm.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03364-3.

Consciousness and cognition in plants

Unlike animal behavior, behavior in plants is traditionally assumed to be completely determined either genetically or environmentally. Under this assumption, plants are usually considered to be noncognitive organisms. This view nonetheless clashes with a growing body of empirical research that shows that many sophisticated cognitive capabilities traditionally assumed to be exclusive to animals are exhibited by plants too. Yet, if plants can be considered cognitive, even in a minimal sense, can they also be considered conscious? Some authors defend that the quest for plant consciousness is worth pursuing, under the premise that sentience can play a role in facilitating plant's sophisticated behavior. The goal of this article is not to provide a positive argument for plant cognition and consciousness, but to invite a constructive, empirically informed debate about it. After reviewing the empirical literature concerning plant cognition, we introduce the reader to the emerging field of plant neurobiology. Research on plant electrical and chemical signaling can help shed light into the biological bases for plant sentience. To conclude, we shall present a series of approaches to scientifically investigate plant consciousness. In sum, we invite the reader to consider the idea that if consciousness boils down to some form of biological adaptation, we should not exclude a priori the possibility that plants have evolved their own phenomenal experience of the world. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Philosophy > Consciousness Neuroscience > Cognition.

Effect of hydric stress-related acoustic emission on transcriptional and biochemical changes associated with a water deficit in Capsicum annuum L

At specific vibration frequencies like ones generated by insects such as caterpillar chewing and bee's buzz-pollination turn on the plants secondary metabolism and their respective pathways gets activated. Thus, studies report that vibrations and sound waves applied to plants improves their fitness performance. Commonly, acoustic treatments for plants have used arbitrarily random frequencies. In this work, a group of signals obtained from hydric-stressed plants was recorded as vibrational patterns using a laser vibrometer. These vibration-signals were classified as representative of each condition and then externally applied as Acoustic Emission Patterns (AEP). The present research hypothesized that specific vibration frequencies could "emulate" a plant signal through mechanical energy based on tplant's ability to recognize vibration pattern similarity to a hydric status. This investigation aimed to apply the AEP's as characteristic vibrations classified as Low hydric stress (LHS), medium hydric stress (MHS), and high hydric stress (HHS) to evaluate their effect on healthy-well watered plants at two developmental stages. In the vegetative stage, the gene expression related to antioxidant and hydric stress responses was assessed. The LHS, MHS, and HHS acoustic treatments up-regulated the peroxidase (Pod) (~2.8, 1.9, and 3.6-fold change, respectively). The superoxide dismutase (Mn-sod) and phenylalanine ammonia-lyase (Pal) genes were up-regulated by HHS (~0.23 and ~0.55-fold change, respectively) and, the chalcone synthase (Chs) gene was induced by MHS (~0.63-fold-change). At the fructification stage, the MHS treatment induced a significant increase in Capsaicin content (5.88-fold change), probably through the at3and kas gene activation. Findings are correlated for a better understanding of plant responses to different multi frequency-signals tones from vibrations with potential for agricultural applications.

Seed 'primeomics': plants memorize their germination under stress

Seed priming is a pre-germination treatment administered through various chemical, physical and biological agents, which induce mild stress during the early phases of germination. Priming facilitates synchronized seed germination, better seedling establishment, improved plant growth and enhanced yield, especially in stressful environments. In parallel, the phenomenon of 'stress memory' in which exposure to a sub-lethal stress leads to better responses to future or recurring lethal stresses has gained widespread attention in recent years. The versatility and realistic yield gains associated with seed priming and its connection with stress memory make a critical examination useful for the design of robust approaches for maximizing future yield gains. Herein, a literature review identified selenium, salicylic acid, poly-ethylene glycol, CaCl₂ and thiourea as the seed priming agents (SPRs) for which the most studies have been carried out. The average priming duration for SPRs generally ranged from 2 to 48 h, i.e. during phase I/II of germination. The major signalling events for regulating early seed germination, including the DOG1 (delay of germination 1)-abscisic acid (ABA)-heme regulatory module, ABA-gibberellic acid antagonism and nucleus-organelle communication are detailed. We propose that both seed priming and stress memory invoke a 'bet-hedging' strategy in plants, wherein their growth under optimal conditions is compromised in exchange for better growth under stressful conditions. The molecular basis of stress memory is explained at the level of chromatin reorganization, alternative transcript splicing, metabolite accumulation and autophagy. This provides a useful framework to study similar mechanisms operating during seed priming. In addition, we highlight the potential for merging findings on seed priming with those of stress memory, with the dual benefit of advancing fundamental research and boosting crop productivity. Finally, a roadmap for future work, entailing identification of SPR-responsive varieties and the development of dual/multiple-benefit SPRs, is proposed for enhancing SPR-mediated agricultural productivity worldwide.

Identification and characterization of long non-coding RNAs regulating resistant starch biosynthesis in bread wheat (Triticum aestivum L.)

Resistant starch (RS) also known as healthy starch has shown several health benefits. Enhancing the RS through genetic modification approaches has huge commercial importance. Regulatory RNA like long non-coding RNA (lncRNA) plays an important role in gene regulation. In this study, we mined 63 transcriptome datasets of wheat belonging to 35 genotypes representing two seed developmental stages. Contrasting expression of a subset of lncRNAs in RS mutant lines compared to parent wheat variety 'C 306' signifies their probable role in RS biosynthesis. Further, lncRNA- TCONS_00130663 showed strong positive correlation (r² = 1) with LYPL gene and strong negative correlation with SBEIIb (r² = -0.94). We found TCONS_00130663 as positive regulator of LYPL gene through interaction with miR1128. Based on relative expression, in silico interaction and DSC analysis we hypothesize the dual role of TCONS_00130663 in RS type 2 and type 5. The study provides a useful resource for functional mechanism of lncRNAs.