Chitosan derivatives act as a bio-stimulants in plants: A review.

Chitosan has been considered an eco-friendly biopolymer. Chitosan is a natural polycationic linear polysaccharide composed of D-glucosamine and N-acetyl-D-glucosamine linked by ß-1,4-glycosidic bonds. Chitosan has been used as an eco-friendly biopolymer for so many agricultural applications. Unfortunately, the relatively poor solubility and poor antimicrobial properties limit its widespread applications in agriculture sciences. Hence, chitosan derivatives are produced via various chemical approaches such as cross-linking, carboxylation, ionic binding, and so on. As an alternative to chemical fertilizers, chitosan derivatives, chitosan conjugates, nanostructures, semisynthetic derivatives, oligo mixes, chitosan nanoparticles, and chitosan nano-carriers are synthesized for various agricultural applications. Its several chemical and physical properties such as biocompatibility, biodegradability, permeability, cost-effectiveness, low toxicity, and environmental friendliness make it useful for many agricultural applications. Hence, popularizing its use as an elicitor molecule for different host-pathogen interaction studies. Thus, the versatile and plethora of chitosan derivatives are gaining momentum in agricultural sciences. Bio-stimulant properties and multifunctional benefits are associated with further prospective research. Therefore, in the present review, we decipher the potential pros and cons of chitosan derivatives in plants.

Microbial Volatile Organic Compounds: An Alternative for Chemical Fertilizers in Sustainable Agriculture Development.

Microorganisms are exceptional at producing several volatile substances called microbial volatile organic compounds (mVOCs). The mVOCs allow the microorganism to communicate with other organisms via both inter and intracellular signaling pathways. Recent investigation has revealed that mVOCs are chemically very diverse and play vital roles in plant interactions and microbial communication. The mVOCs can also modify the plant's physiological and hormonal pathways to augment plant growth and production. Moreover, mVOCs have been affirmed for effective alleviation of stresses, and also act as an elicitor of plant immunity. Thus, mVOCs act as an effective alternative to various chemical fertilizers and pesticides. The present review summarizes the recent findings about mVOCs and their roles in inter and intra-kingdoms interactions. Prospects for improving soil fertility, food safety, and security are affirmed for mVOCs application for sustainable agriculture.

A status-quo review on CRISPR-Cas9 gene editing applications in tomato.

Epigenetic changes are emancipated in horticultural crops including tomato due to a variety of environmental factors. These modifications rely on plant phenotypes mediated by genetic architecture consequently resulting in hereditary epigenetic memory. Genome editing strategies like CRISPR (Clustered Regularly Interspaced Short Palindromic Repeat)/CRISPR-associated protein 9 (Cas9) technologies have revolutionized plants biology foreseeing stable inheritance of epigenetic modifications. CRISPR/Cas9 strategy poses as explicit advancement in providing precise genome editing with minimal off-target mutations, ease of experimental design, higher efficiency, versatility, and cost-effectiveness. Dicot crops, especially tomato remain an ideal candidate for CRISPR/Cas9 based gene modulations thereby augmenting productivity and yields. In the present review, key questions on CRISPR/Cas9 applications aid in enhanced growth based on optimal gene discovery, de novo modification, trait improvement, and biotic/abiotic stress management are discussed. In addition, comparative scenario in tomato and similar horticultural crops are adequately summarized for the pros and cons. Further, limitations hampering potential benefits and success phenomena of the lab to field transition of gene editing alterations are discussed collaterally in addressing futuristic optimization for CRISPR/Cas9 research in tomato.

Bacillus subtilis CBR05 induces Vitamin B6 biosynthesis in tomato through the de novo pathway in contributing disease resistance against Xanthomonas campestris pv. vesicatoria.

Expression profiling for genes involved in Vitamin B6 (VitB6) biosynthesis was undertaken to delineate the involvement of de novo and salvage pathway induced by Bacillus subtilis CBR05 against, Xanthomonas campestris pv. vesicatoria in tomato. Pyridoxine biosynthesis (PDX) genes such as PDX1.2 and PDX1.3, were found to be overexpressed significantly at 72 hpi in B. subtilis and pyridoxine inoculated plants. Most significant upregulation was observed in the transcript profile of PDX1.3, which showed more than 12- fold increase in expression. Unfortunately, salt sensitive overlay4 (SOS4) profiling showed irregular expression which corroborates that SOS4 role in VitB6 biosynthesis needs further studies for deciphering a clear notion about their role in tomato. Antioxidant enzymes i.e., superoxide dismutase, catalase, polyphenol oxidase, and peroxidase activities clearly demonstrate escalation till 48 hpi and gets reduced in 72 hpi. Pot trials also confirm that B. subtilis compared to pyridoxine supplementation alone show plant disease resistance and elongated roots. The present study confirms that B. subtilis, as a versatile agent in eliciting induced systemic resistance regulated by de novo pathway as a model for plant defense against X. campestris pv. vesicatoria substantiated by VitB6 biosynthesis. Nevertheless, the study is preliminary and needs further evidence for affirming this phenomenon.

Proline Accumulation Influenced by Osmotic Stress in Arbuscular Mycorrhizal Symbiotic Plants.

Salinity and drought are the major osmotic stress limitations that affect plant growth and crop yield in agriculture worldwide. The alternative response mediated by plants in response to salinity and drought are principally proline accumulation which regulates stress combat strategies owing to sustainable production in the realm of agricultural production even under severe stress. Symbiotic and soil associated arbuscular mycorrhizal fungi (AMF) are regarded as efficient biofertilizers in several crops under these stresses. Summarily AMF is renowned for effective scavengers of free radicals in soil thereby increasing soil parameters optimal for plant growth. AMF contribute to augment host plant tolerance to stress specifically salinity and drought. Mycorrhizal colonization positively regulates root uptake of available nutrients and enhance growth even when bestowed by water constraints which has contributory roles due to proline accumulation providing several intriguing researches on AMF symbiosis pertaining to plant productivity and yield. Mycorrhizal plants and their non-mycorrhizal counterparts show varied expression pattern regarding proline amass. Hence, the precise role of proline with respect to stress tolerance and equivocal mechanisms involved in evasion of osmotic stress has not been extensively reviewed earlier. Further molecular forecasting in this arena is still an underexploited research field. This review comprehensively addresses the observable facts pertaining to proline accumulation upon AMF association and adherence relevant to stress tolerance and host plant efficiency and efficacy.

Molecular modelling of urease accessory interaction proteins of Helicobacter Pylori J 99 and predicting an interruption in interaction by Vigna radiata Defensins.

Helicobacter pylori is the major causative agent of Gastric carcinoma. Significance of the urease accessory interaction proteins are emphasized in colonization of human gastric mucosa and efficient infection of H. pylori. Here an attempt is made to explore the structure and properties of urease accessory interaction proteins from Helicobacter pylori J 99. The proteins chosen for the study are ureH, ureI, nikR, groL and flgS based on the interaction map available from STRING database. The above mentioned proteins do not have a comprehensive three dimensional structure. Hence the models were generated using PSI-BLAST (Position Specific Iterative-Blast) and MODELLER 9V8. Physicochemical characterization encompasses pI, EC, AI, II and GRAVY. Secondary structure was predicted using PSI-PRED. Functional characterization was done by SOSUI and DISULFIND Servers and refinement of structure was done using Ramachandran plot analysis. RMS-Z values were calculated using Q-MEAN Server and CHIMERA was used for molecular simulation studies. Plant defensins from Vigna radiata are successfully docked to the modeled structures and thus interaction could be possibly prevented. These results will pave way for further selective inhibition of H. pylori colonization and in vivo survival by employing plant defensins from Vigna radiata (VrD1 & VrD2). The work will prove that plant defensins provides anticancer relief too.