Improving the Aroma of Millets by Targeting the Betaine Aldehyde Dehydrogenase 2 Gene: A Promising Approach for Popularising Millet Foods Worldwide

Two gramineae species, Panicum maximum and Eleusine coracana, were exposed to salinity stress and leaf water status, solute concentrations in cell sap, levels of betaine aldehyde dehydrogenase (BADH) and BADH mRNA were measured. Panicum maximum was able to maintain a high turgor and high relative water content at low leaf water potentials, and this was associated with the greater capacity for osmotic adjustment. Major osmotica in Panicum maximum leaves were Na+, Cl-, sugar and glycinebetaine, and these solutes were increased by salinity. Na+ and glycinebetaine concentrations in Eleusine coracana leaves also were increased by salt stress, but these solutes were in significantly lower concentrations than those measured in Panicum maximum. BADH enzyme activity and BADH mRNA levels in Panicum maximum leaves were both increased by salt stress, and their expression coincided with the observed betaine accumulation. Although the addition of abscisic acid (ABA) to leaf disks of Panicum maximum plants also increased BADH mRNA levels, these were smaller than those observed in NaCl treated leaves.

Two gramineae species, Panicum maximum and Eleusine coracana, were exposed to salinity stress and leaf water status, solute concentrations in cell sap, levels of betaine aldehyde dehydrogenase (BADH) and BADH mRNA were measured. Panicum maximum was able to maintain a high turgor and high relative water content at low leaf water potentials, and this was associated with the greater capacity for osmotic adjustment. Major osmotica in Panicum maximum leaves were Na+, Cl−, sugar and glycinebetaine, and these solutes were increased by salinity. Na+ and glycinebetaine concentrations in Eleusine coracana leaves also were increased by salt stress, but these solutes were in significantly lower concentrations than those measured in Panicum maximum. BADH enzyme activity and BADH mRNA levels in Panicum maximum leaves were both increased by salt stress, and their expression coincided with the observed betaine accumulation. Although the addition of abscisic acid (ABA) to leaf disks of Panicum maximum plants also increased BADH mRNA levels, these were smaller than those observed in NaCl treated leaves.

7 - Finger and foxtail millets

BackgroundThe nucleotide binding site leucine rich repeat (NBLRR) genes significantly regulate defences against phytopathogens in plants. The genome-wide identification and analysis of NBLRR genes have been performed in several species. However, the detailed evolution, structure, expression of NBLRRs and functional response to Magnaporthe grisea are unknown in finger millet (Eleusine coracana (L.) Gaertn.).ResultsThe genome-wide scanning of the finger millet genome resulted in 116 NBLRR (EcNBLRRs1-116) encompassing 64 CC-NB-LRR, 47 NB-LRR and 5 CCR-NB-LRR types. The evolutionary studies among the NBLRRs of five Gramineae species, viz., purple false brome (Brachypodium distachyon (L.) P.Beauv.), finger millet (E. coracana), rice (Oryza sativa L.), sorghum (Sorghum bicolor L. (Moench)) and foxtail millet (Setaria italica (L.) P.Beauv.) showed the evolution of NBLRRs in the ancestral lineage of the target species and subsequent divergence through gene-loss events. The purifying selection (Ka/Ks < 1) shaped the expansions of NBLRRs paralogs in finger millet and orthologs among the target Gramineae species. The promoter sequence analysis showed various stress- and phytohormone-responsive cis-acting elements besides growth and development, indicating their potential role in disease defence and regulatory mechanisms. The expression analysis of 22 EcNBLRRs in the genotypes showing contrasting responses to Magnaporthe grisea infection revealed four and five EcNBLRRs in early and late infection stages, respectively. The six of these nine candidate EcNBLRRs proteins, viz., EcNBLRR21, EcNBLRR26, EcNBLRR30, EcNBLRR45, EcNBLRR55 and EcNBLRR76 showed CC, NB and LRR domains, whereas the EcNBLRR23, EcNBLRR32 and EcNBLRR83 showed NB and LRR somains.ConclusionThe identification and expression analysis of EcNBLRRs showed the role of EcNBLRR genes in assigning blast resistance in finger millet. These results pave the foundation for in-depth and targeted functional analysis of EcNBLRRs through genome editing and transgenic approaches.

BACKGROUND: Millets are a group of variable small seeded grass, widely grown around the world as cereals crop. The finger millet had more moisture and calcium content. Whereas, fat content was least when compared to three other different millets. Foxtail millets had more protein content, pearl millets had more zinc and proso millets had more carbohydrate and fat content. AIM: To determine the proximate constituent and micronutrient content of finger millet, foxtail millet, pearl millet and proso millet. OBJECTIVES: To analyse the moisture, carbohydrate, fat, and protein content of finger millet, foxtail millet, pearl millet, proso millet by standard methods of AOAC. To analyse the calcium and zinc content of finger millet, foxtail millet, pearl millet, proso millet by atomic absorption spectrophotometer.MATERIALS AND METHODS: Proximate analysis of samples (moisture content, carbohydrate, protein, fat, calcium and zinc) was performed by standard methods of Association of Official Analytical Chemist (AOAC).RESULTS AND CONCLUSION: The mean values of finger millet for moisture content (12.86 ± 0.95) had highest and fat content (1.58 ± 0.36) was least. In foxtail millet protein content (12.94 ± 0.87) was highest and in pearl millet zinc content (3.29 ± 0.47) was highest. In proso millet fat content (12.80 ± 0.30) and carbohydrate content 75.06 ± 7.3) was highest when compared to the other millet. Calcium (344.45 ± 2.62) had highest in finger millet whereas pearl millet zinc content (3.29 ± 0.47) was highest when compared to the other millets. Hence, the study results can be useful for informing the people to select the different millets depending upon the nutritional needs.

The power and versatility of genome editing tools in crop improvement

Current agricultural and food systems encourage research and development on major crops, neglecting regionally important minor crops. Small millets include a group of small- seeded cereal crops of the grass family Poaceae. This includes finger millet, foxtail millet, proso millet, barnyard millet, kodo millet, little millet, teff, fonio, job’s tears, guinea millet, and browntop millet. Small millets are an excellent choice to supplement major staple foods for crop and dietary diversity because of their diverse adaptation on marginal lands, less water requirement, lesser susceptibility to stresses, and nutritional superiority compared to major cereal staples. Growing interest among consumers about healthy diets together with climate-resilient features of small millets underline the necessity of directing more research and development towards these crops. Except for finger millet and foxtail millet, and to some extent proso millet and teff, other small millets have received minimal research attention in terms of development of genetic and genomic resources and breeding for yield enhancement. Considerable breeding efforts were made in finger millet and foxtail millet in India and China, respectively, proso millet in the United States of America, and teff in Ethiopia. So far, five genomes, namely foxtail millet, finger millet, proso millet, teff, and Japanese barnyard millet, have been sequenced, and genome of foxtail millet is the smallest (423-510 Mb) while the largest one is finger millet (1.5 Gb). Recent advances in phenotyping and genomics technologies, together with available germplasm diversity, could be utilized in small millets improvement. This review provides a comprehensive insight into the importance of small millets, the global status of their germplasm, diversity, promising germplasm resources, and breeding approaches (conventional and genomic approaches) to accelerate climate-resilient and nutrient-dense small millets for sustainable agriculture, environment, and healthy food systems.

Gelatinisation and Rheological Characteristics of Minor Millet Flours

A plethora of studies have uncovered numerous important genes with agricultural significance in staple crops. However, when it comes to orphan crops like minor millet, genomic research lags significantly behind that of major crops. This situation has promoted a focus on exploring research opportunities in minor millets, particularly in finger millet, using cutting-edge methods. Finger millet, a coarse cereal known for its exceptional nutritional content and ability to withstand environmental stresses represents a promising climate-smart and nutritional crop in the battle against escalating environmental challenges. The existing traditional improvement programs for finger millet are insufficient to address global hunger effectively. The lack of utilization of high-throughput platforms, genome editing, haplotype breeding, and advanced breeding approaches hinders the systematic multi-omics studies on finger millet, which are essential for pinpointing crucial genes related to agronomically important and various stress responses. The growing environmental uncertainties have widened the gap between the anticipated and real progress in crop improvement. To overcome these challenges a combination of cutting-edge multi-omics techniques such as high-throughput sequencing, speed breeding, mutational breeding, haplotype-based breeding, genomic selection, high-throughput phenotyping, pangenomics, genome editing, and more along with integration of deep learning and artificial intelligence technologies are essential to accelerate research efforts in finger millet. The scarcity of multi-omics approaches in finger millet leaves breeders with limited modern tools for crop enhancement. Therefore, leveraging datasets from previous studies could prove effective in implementing the necessary multi-omics interventions to enrich the genetic resource in finger millet.

The synthesis of the osmoprotectant glycine betaine (GB) in plants is a metabolic trait of major adaptive importance since it confers tolerance to drought, saline soils and cold, but only some plants can synthesize and accumulate GB. Also, the GB content of a plant is valuable for human and animal nutrition. GB is synthesized from choline in two consecutive reactions catalyzed by choline mono-oxygenase (CMO) and betaine aldehyde dehydrogenase (BADH). Nonaccumulators plants have very low levels of BADH activity due to a single change in an amino acid residue of this enzyme. Two CMO isoenzymes also appear to exist, but they have not been biochemically and structurally characterized yet. Another factor that limits the synthesis of GB is the supply of choline to CMO. Most likely, in GB-accumulator plants the catalytic activities and the regulation of the expression of both BADH and CMO proteins coevolved, since the BADH activity requires an active CMO, and an active CMO without an active BADH would be deleterious for the plant because the toxic betaine aldehyde would accumulate. Biotechnological efforts to engineer this important metabolic trait in GB-nonaccumulators crops have had limited success so far, stressing the need for more basic biochemical studies.

Millets are renowned for their climatic resilience and possess high nutritive value with wide genetic variations. In countries like India and Africa, millets are part of many people's regular diets with rich sources of protein, dietary fiber, polyphenols, minerals, vitamins, and other nutrients. The proteomic signatures of several millet species, including Fonio, Finger, Proso, Sorghum, and Foxtail millet, were examined in this study. We have performed orthologous analysis to discover both common and distinctive protein clusters among these species by using the OrthoFinder algorithm in conjunction with visualization tools. A total of 16,247 clusters were shared by all species, offering light on similar evolutionary or adaptation mechanisms. The strong representation of Gene Ontology (GO) categories related to osmotic stress, water deprivation, and temperature stresses in the research further highlighted the millets' powerful adaptative responses to various environmental difficulties. Intricate signaling mechanisms for wound, defense, and growth are also revealed by their efficient photosynthetic capacities. However, each species' distinctive clusters, particularly those in Finger millet, highlighted how it differed from other millets. The evolutionary links were further clarified by a phylogenetic tree built using the Maximum likelihood approach and the JTT+CAT evolutionary model, with Foxtail and Proso millets showing a closer kinship. The research sheds light on the complex genetic network of millets, evolutionary histories, and potential adaptive processes. The identification of 2,277 clusters, which are mainly shared by foxtail, proso, fonio, and sorghum millets and support the distinct evolutionary history of finger millet, was especially important. These millets' strong adaptive mechanisms, which are on display in clusters related to different response mechanisms, demonstrate their evolutionary skill and point to prospective directions for crop improvement and resilience techniques.

Some experiments on transpiration and water absorption were conducted to determine the different rooting ability of millets at the time of transplanting from the viewpoint of water balance in the plant. This report also contains work on the effect of seedling quality on rooting. These experiments were done during the period from 1978 to 1981. The results obtained were as follows: 1. Transpiration rate per leaf arca was the highest in Japanese barnyard millet and the lowest in sorghum under the condition of water culture. Among the seedlings from the nursery bed filled with volcanic soil, however, Italian millet showed the highest transpiration, and the low values were seen in common millet and Japanese barnyard millet (Table 1). 2. The reason why Italian millet was subject to losing water balance in the plant at transplanting time, compared with finger millet were as follows: (1) Water content of the plant organs was lower in Italian millet and its transpiration rate was higher. This might be due to the higher stomata density per leaf area. (2) Top/Root ratio of Italian millet is extremely high and it becomes still higher by unavoidable cutting of roots at the time of transplanting. This results in a considerable decrease in water absorption by roots, although Italian millet has high water absorption rate and high level of bleeding water per root dry matter weight. This decrease in water absorption compared to a higher transpiration rate of leaves may result in losing water balance in Italian millet. On the other hand, finger millet had lower water absorption and also lower bleeding water level per root dry matter weight. But this crop had a high water content in its plant organs and a lower ratio of Top/Root. Therefore, the water balance can be kept in the plant. In the case of sorghum, ablility of water absorption and bleeding was low and the water balance in the plant may be kept with lower water contents because of its lower transpiration rate due to fewer stomata per leaf area. Japanese barnyard millet and common millet showed a similar tendency to finger millet and Italian millet, respectively (Table 2 and 3, Figs. 4-5). 3. To understand the effect of seedling quality on taking root, the rooting ability of seedlings grown at different fertilizer levels was investigated. New roots were more numerous in the seedlings of the standard fertilizer plot than the non-fertilizer application plot. The longest root was found in the seedling of the non-fertilizer plot. In the high fertilizer plot, only finger millet could produce more roots. Two weeks after transplanting, plants from the standard level plot showed greater growth, whereas common millet, Japanese barnyard millet and Italian millet displayed less growth at a higher level of fertilizer than the standard level (Table 4 and 5). From the above results, the higher Top/Root ratio is likely to cause taking root to fail at transplanting mainly due to damage of roots by pulling seedlings from the nursery bed, and the resultant decrease of water absorption by roots and loss of water balance in the plant can be seen. Therefore, especially the direct sowing type plants such as Italian millet and common millet are not suitable for transplanting. As to the effect of seeding quality on taking root, the seedings grown at the standard fertilizer levels generally showed good growth with many newly-emerged roots. But with a higher fertilizer level, all the millets except finger millet could not attain desirable growth.

Aim: The present study was conducted to evaluate the proximate analysis, mineral composition, antioxidant activity and resistant starch of finger millet flour and foxtail millet flour and their comparison with refined wheat flour. Introduction: Finger millet grain and foxtail millet grain were procured from district Champawat, Uttarakhand, India. Recent studies indicated that minor millets such as foxtail and finger millet are nutritionally superior to conventional food grains and exhibit hypoglycemic effects due to the presence of a higher proportion of complex carbohydrates, resistant starch and slow-rising sugars. Method: Proximate analysis of finger millet flour, foxtail millet flour and refined wheat flour was done by standard method. All the samples were analysed in three replicates. Resistant starch yield was determined by using the glucose oxidase assay. The antioxidant activity of finger millet flour, foxtail millet flour and refined wheat flour method with some modifications. Results: The results of the proximate analysis showed a significantly higher amount of total ash (2.51 %), crude protein (12.23 %), crude fat (3.49 %), crude fiber (4.79%), and energy (353 kcal) in foxtail millet flour as compared to finger millet flour and refined wheat flour. The insoluble dietary fiber content was significantly higher for foxtail millet flour (11.01%). However, finger millet flour contained significantly higher amounts of soluble dietary fiber (7.00%) and total dietary fiber (17.06%) than foxtail millet flour and controlled refined wheat flour. Foxtail millet flour contained a higher amount of resistant starch (15.10 %) than finger millet flour (14.85%) and refined wheat flour (1.01 %). Conclusion: Total antioxidant activity was also found highest in finger millet flour (71.07 %) as compared to foxtail millet flour (65.85%) and refined wheat flour (20.62%). Finger millet flour contained significantly higher amount of soluble dietary fibre than foxtail millet flour and refined wheat flour. However, soluble dietary fibre content of foxtail millet flour was significantly higher than refined wheat flour.

Finger millet was the most consumed among the urban consumers with 3.00 kg per month while other millets equally being consumed by the urban consumers, while foxtail millet, finger millet and little millet were consumed by rural consumers with higher consumption of foxtail millet. The monthly household food expenditure among the urban consumers, expenses made on groceries (40.21 percentage), expenditure on millet (15.33 percentage), purchasing minor millets were as nutritional and health benefits (96.67 percentage) followed by doctor’s advice (53.33 percentage) similarly, traditional staple food (93.33 percentage) followed by own production (80.00 percentage) for rural households. For each respondent, the part-worth’s were estimated using OLS regression analysis, rural consumers also found price to be the most important attribute accounting 26.11 per cent of relative importance, gaining awareness among consumers in consumption of millets for nutritional value and health benefits is improving gradually

Chapter 7 - Biotic stresses and their management