Effects of fuzzless cottonseed phenotype on cottonseed nutrient composition in near isogenic cotton (Gossypium hirsutum L.) mutant lines under well-watered and water stress conditions

Genetic Mapping for QTL Associated with Seed Nickel and Molybdenum Accumulation in the Soybean 'Forrest' by 'Williams 82' RIL Population

Understanding the genetic basis of seed Ni and Mo is essential. Since soybean is a major crop in the world and a major source for nutrients, including Ni and Mo, the objective of the current research was to map genetic regions (quantitative trait loci, QTL) linked to Ni and Mo concentrations in soybean seed. A recombinant inbred line (RIL) population was derived from a cross between 'Forrest' and 'Williams 82' (F × W82). A total of 306 lines was used for genotyping using 5405 single nucleotides polymorphism (SNP) markers using Infinium SNP6K BeadChips. A two-year experiment was conducted and included the parents and the RIL population. One experiment was conducted in 2018 in North Carolina (NC), and the second experiment was conducted in Illinois in 2020 (IL). Logarithm of the odds (LOD) of ≥2.5 was set as a threshold to report identified QTL using the composite interval mapping (CIM) method. A wide range of Ni and Mo concentrations among RILs was observed. A total of four QTL (qNi-01, qNi-02, and qNi-03 on Chr 2, 8, and 9, respectively, in 2018, and qNi-01 on Chr 20 in 2020) was identified for seed Ni. All these QTL were significantly (LOD threshold > 2.5) associated with seed Ni, with LOD scores ranging between 2.71-3.44, and with phenotypic variance ranging from 4.48-6.97%. A total of three QTL for Mo (qMo-01, qMo-02, and qMo-03 on Chr 1, 3, 17, respectively) was identified in 2018, and four QTL (qMo-01, qMo-02, qMo-03, and qMo-04, on Chr 5, 11, 14, and 16, respectively) were identified in 2020. Some of the current QTL had high LOD and significantly contributed to the phenotypic variance for the trait. For example, in 2018, Mo QTL qMo-01 on Chr 1 had LOD of 7.8, explaining a phenotypic variance of 41.17%, and qMo-03 on Chr 17 had LOD of 5.33, with phenotypic variance explained of 41.49%. In addition, one Mo QTL (qMo-03 on Chr 14) had LOD of 9.77, explaining 51.57% of phenotypic variance related to the trait, and another Mo QTL (qMo-04 on Chr 16) had LOD of 7.62 and explained 49.95% of phenotypic variance. None of the QTL identified here were identified twice across locations/years. Based on a search of the available literature and of SoyBase, the four QTL for Ni, identified on Chr 2, 8, 9, and 20, and the five QTL associated with Mo, identified on Chr 1, 17, 11, 14, and 16, are novel and not previously reported. This research contributes new insights into the genetic mapping of Ni and Mo, and provides valuable QTL and molecular markers that can potentially assist in selecting Ni and Mo levels in soybean seeds.

Muscle Nutritive Metabolism Changes after Dietary Fishmeal Replaced by Cottonseed Meal in Golden Pompano (Trachinotus ovatus)

Our previous study demonstrated that based on growth performance and feed utilization, cottonseed meal (CSM) could substitute 20% fishmeal (FM) without adverse effect on golden pompano (Trachinotus ovatus). Muscle deposition was also an important indicator to evaluate the efficiency of alternative protein sources. Therefore, the present study was conducted to explore the changes of physiobiochemical and nutrient metabolism in muscle after FM replaced by CSM. Four isonitrogenous and isolipidic experimental diets (42.5% crude protein, 14.0% crude lipid) were formulated to replace 0% (CSM0 diet), 20% (CSM20 diet), 40% (CSM40 diet), and 60% (CSM60 diet) of FM with CSM. Juvenile fish (24.8 ± 0.02 g) were fed each diet for 6 weeks. The results presented, which, compared with the CSM0 diet, CSM20 and CSM40 diets, had no effect on changing the muscle proximate composition and free essential amino acid (EAA) concentration. For glycolipid metabolism, the CSM20 diet did not change the mRNA expression of hexokinase (hk), glucose transport protein 4 (glut4), glucagon-like peptide 1 receptor (glp-1r), while over 20% replacement impaired glucose metabolism. However, CSM20 and CSM40 diets had no effect on altering lipid metabolism. Mechanistically, compared with the CSM0 diet, the CSM20 diet did not change muscle nutritive metabolism through keeping the activities of the nutrient sensing signaling pathways stable. Higher replacement would break this balance and lead to muscle nutritive metabolism disorders. Based on the results, CSM could substitute 20-40% FM without affecting the muscle nutritive deposition. All data supplemented the powerful support for our previous conclusion that CSM could successfully replace 20% FM based on growth performance.

Change in cotton plant quality in response to application of anaerobically digested sewage sludge

Treated municipal sewage sludge (TSS) was applied to the cotton plant at rates of 10, 20 and 30 t/ha per year. Seed cotton yield (71.4%), lint yield (67.7%) and cottonseed yield (74.1%) were increased significantly when sludge was applied at a rate of 30 t/ha (TSS3). The effects of TSS applications on seed yield, lint yield and cottonseed yield were listed as TSS3 > TSS2 > CF > TSS1 > C according to the applications. The increasing TSS levels had a positive effect and increased the total N concentration compared to the control. The highest N value was observed in TSS3 plots, while the lowest value was recorded in control (C) plots. The highest P value was found in control (C) at 0.80% and in 10 t/ha (TSS1) at 0.80%, while the lowest value was found in the TSS2 application (0.70%). The K concentration of cottonseed increased with the increasing TSS rates, from 1.56% in control plots to 2.20% in 20 t/ha application (TSS2). Corresponding to the TSS levels, the calcium of plant tissues was determined by a range of 0.12–0.13%. The treatments of TSS and mineral fertilizer had similar effects on the Mg content of cottonseed, which was in the range of 0.38–0.43%. Na content in plant tissue increased with increasing dose of sludge application compared to control soils. Increasing doses of TSS had no significant effect on the concentrations of iron (Fe), copper (Cu), zinc (Zn), manganese (Mn) and boron (B) in cottonseed. The order of the elements with respect to their amounts in cottonseed was as follows: Fe > Zn > Na > B > Mn > Cu. The concentrations of non-essential elements (Ni, Cd, Cr, Pb, Hg and As) in cottonseed were below the permissible limits.

Influence of Curly Leaf Trait on Cottonseed Micro-Nutrient Status in Cotton (Gossypium hirsutum L.) Lines

Cottonseed is a source of nutrients, including protein, oil, and macro- and micro-nutrients. Micro-nutrients such as boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) are essential for plant and human health. Deficiencies of these micro-nutrients in soil lead to poor crop production and poor seed quality. Micro-nutrient deficiencies in the human diet lead to malnutrition and serious health issues. Therefore, identifying new cotton lines containing high nutritional qualities such as micro-nutrients, and understanding plant traits influencing micro-nutrients are essential. The objective of this research was to investigate the effects of leaf shape (curly leaf: CRL) on cottonseed B, Cu, Fe, Mn, Ni (nickel), and Zn in two near-isogenic cotton lines differing in leaf shape (DP 5690 wild-type with normal leaves and DP 5690 CRL). We also used Uzbek CRL, the source of the curly leaf trait, for comparison. A field experiment was conducted in 2014 and 2015 in Stoneville, MS, USA. The experiment was a randomized complete block design with three replicates. The results showed that, in 2014, both DP 5690 wild-type and Uzbek CRL had higher seed B, Cu, Fe, and Ni than in DP 5690 CRL. The accumulation of Mn and Zn in seeds of DP 5690 CRL was higher than in DP 5690 wild-type and Uzbek CRL. However, in 2015, the concentrations of B, Cu, Fe, and Ni, including Mn and Zn, were higher in both DP 5690 wild-type and Uzbek CRL than in DP 5690 CRL. Positive and negative correlations existed in 2014; however, only positive correlations existed between all nutrients in 2015. This research demonstrated that leaf shape can alter cottonseed micro-nutrients status. As Uzbek CRL behaved similar to wild-type, both leaf shape and other factors contributed to the alteration in seed micronutrients, affecting seed nutritional qualities. Therefore, leaf-shape partially contributed to the changes in micro-nutrients in cottonseed. The negative and positive correlations in 2014, and only positive correlations in 2015, were likely due to the heat difference between 2014 and 2015 as 2015 was warmer than 2014. Significant levels of seed micro-nutrients were shown between these lines, providing opportunities for breeders to select for high seed micro-nutrients in cotton. Additionally, the current research provides researchers with physiological information on the impact of leaf shape on seed nutritional quality. The leaf shape trait can also be used as a tool to study leaf development, physiological, biochemical, and morphological processes.

Cottonseed Protein, Oil, and Minerals in Cotton (Gossypium hirsutum L.) Lines Differing in Curly Leaf Morphology

Cottonseed is an important source of protein, oil, and minerals for human health and livestock feed. Therefore, understanding the physiological and genetic traits influencing the nutrient content is critical. To our knowledge, there is no information available on the effects of leaf shape—curly leaf (CRL)—on cottonseed protein, oil, and minerals. Therefore, the objective of the current research was to investigate the effect of the curly leaf trait on cottonseed protein, oil, and minerals in cotton lines differing in leaf shape. Our hypothesis was that since leaf shape is known to be associated with nutrient uptake, assimilation, and photosynthesis process, leaf shape can influence seed protein, oil, and minerals. A two-year field experiment using two curly leaf lines (Uzbek CRL and DP 5690 CRL) and one normal leaf (DP 5690 wild type) line was conducted in 2014 and 2015 in Stoneville, MS, USA. The experiment was a randomized complete block design with three replicates. The results showed that both Uzbek CRL and DP 5690 wild type lines had higher seed oil, and nutrients N, P, K, and Mg than DP 5690 CRL. Calcium was higher in DP 5690 CRL for two years and protein was only higher than the parents in 2015. Consistent significant positive and negative correlations between some nutrients were observed, which may be due to environmental conditions, especially heat. This indicates that curly leaf trait may partially regulate the accumulation of these nutrients in seeds. The results demonstrated that leaf shape trait—curly leaf—can affect cottonseed nutritional qualities. This research is important to breeders for cotton selection for high seed oil or protein, and to other researchers to further understand the genetic impact of leaf shapes on seed nutritional quality. It is also important for scientists to use leaf shape as a tool for physiological, biochemical, and morphological research related to leaf development.

Protein profiling of water and alkali soluble cottonseed protein isolates

Currently, there is only limited knowledge on the protein types and structures of the cottonseed proteins. In this work, water-soluble cottonseed proteins (CSPw) and alkali-soluble cottonseed proteins (CSPa) were sequentially extracted from defatted cottonseed meal. Proteins of the two fractions were separated by 4–20% gradient polyacrylamide gel electrophoresis (SDS-PAGE); There were 7 and 12 polypeptide bands on SDS-PAGE of CSPa and CSPw, respectively. These individual bands were then excised from the gel and subjected to mass spectrometric analysis. There were total 70 polypeptides identified from the proteins of the two cottonseed preparations, with molecular weights ranging from 10 to 381 kDa. While many proteins or their fragments were found in multiple bands, 18 proteins appeared only in one SDS-PAGE band (6 in CSPa, 12 in CSPw). Putative functions of these proteins include storage, transcription/translation, synthesis, energy metabolism, antimicrobial activity, and embryogenesis. Among the most abundant are legumin A (58 kDa), legumin B (59 kDa), vicilin C72 (70 kDa), vicilin GC72-A (71 kDa), and vicilin-like antimicrobial peptides (62 kDa). This work enriched the fundamental knowledge on cottonseed protein composition, and would help in better understanding of the functional and physicochemical properties of cottonseed protein and for enhancing its biotechnological utilization.

Water Stress and Foliar Boron Application Altered Cell Wall Boron and Seed Nutrition in Near-Isogenic Cotton Lines Expressing Fuzzy and Fuzzless Seed Phenotypes

Our previous research, conducted under well-watered conditions without fertilizer application, showed that fuzziness cottonseed trait resulted in cottonseed nutrition differences between fuzzy (F) and fuzzless (N) cottonseed. Under water stress conditions, B mobility is further limited, inhibiting B movement within the plant, affecting seed nutrition (quality). Therefore, we hypothesized that both foliar B and water stress can affect B mobility, altering cottonseed protein, oil, and mineral nutrition. The objective of the current research was to evaluate the effects of the fuzziness seed trait on boron (B) and seed nutrition under water stress and foliar B application using near-isogenic cotton lines (NILs) grown in a repeated greenhouse experiment. Plants were grown under-well watered conditions (The soil water potential was kept between -15 to -20 kPa, considered field capacity) and water stress conditions (soil water potential between -100 and -150 kPa, stressed conditions). Foliar B was applied at a rate of 1.8 kg B ha(-1) as H3BO3. Under well-watered conditions without B the concentrations of seed oil in N lines were higher than in F lines, and seed K and N levels were lower in N lines than in F lines. Concentrations of K, N, and B in leaves were higher in N lines than in F lines, opposing the trend in seeds. Water-stress resulted in higher seed protein concentrations, and the contribution of cell wall (structural) B to the total B exceeded 90%, supporting the structural role of B in plants. Foliar B application under well-watered conditions resulted in higher seed protein, oil, C, N, and B in only some lines. This research showed that cottonseed nutrition differences can occur due to seed fuzziness trait, and water stress and foliar B application can alter cottonseed nutrition.

Chemical Composition of Defatted Cottonseed and Soy Meal Products

Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as well as total protein isolates. The contents of gossypol, total protein and amino acids, fiber and carbohydrates, and selected macro and trace elements in these products were determined and compared with each other and with those of soy meal products. Data reported in this work improved our understanding on the chemical composition of different cottonseed meal products that is helpful for more economical utilization of these products. These data would also provide a basic reference for product standards and quality control when the production of the cottonseed meal products comes to pilot and industrial scales.

Cottonseed protein, oil, and mineral status in near-isogenic Gossypium hirsutum cotton lines expressing fuzzy/linted and fuzzless/linted seed phenotypes under field conditions

Cotton is an important crop in the world and is a major source of oil for human consumption and cotton meal for livestock. Cottonseed nutrition (seed composition: protein, oil, and minerals) determines the quality of seeds. Therefore, maintaining optimum levels of cottonseed nutrition is critical. Physiological and genetic mechanisms controlling the levels of these constituents in cottonseed are still largely unknown. Our previous research conducted under greenhouse conditions showed that seed and leaf nutrition differed between fuzzless and fuzzy seed isolines. Therefore, the objective of this research was to investigate the seed fuzz phenotype (trait) effects on seed protein, oil, N, C, S, and minerals in five sets of near-isogenic mutant cotton lines for seed fuzz in a 2-year experiment under field condition to evaluate the stability of the effect of the trait on seed nutrition. The isolines (genotypes) in each set differ for the seed fuzz trait (fuzzless/linted seed line, N lines, and fuzzy/linted seed line, F lines). Results showed that seed protein was higher in the fuzzy genotype in all sets, but seed oil was higher in fuzzless genotype in all sets. The concentrations of seed Ca and C were higher in all fuzzless genotypes, but N, S, B, Fe, and Zn were higher in most of the fuzzy genotypes. Generally, minerals were higher in leaves of F lines, suggesting the translocation of minerals from leaves to seeds was limited. The research demonstrated that fiber development could be involved in cottonseed composition. This may be due to the involvement of fiber development in carbon and nitrogen metabolism, and the mobility of nutrients from leaves (source) to seed (sink). This information is beneficial to breeders to consider fuzzless cottonseed for potential protein and oil use and select for higher oil or higher protein content, and to physiologists to further understand the mobility of minerals to increase the quality of cottonseed nutrition for food and feed.