Naturally Colored Cotton Research Articles

Naturally colored cotton for wearable applications.

Naturally colored cotton (NCC) offers an environmentally friendly fiber for textile applications. Processing white cotton fiber into textiles requires extensive energy, water, and chemicals, whereas processing of NCC skips the most polluting activity, scouring-bleaching and dyeing; therefore, NCC provides an avenue to minimize the harmful impacts of textile production. NCC varieties are suitable for organic agriculture since they are naturally insect and disease-resistant, salt and drought-tolerant. Various fiber shades, ranging from light green to tan and brown, are available in the cultivated NCC (Gossypium hirsutum L.) species. The pigments responsible for the color of brown cotton fiber are proanthocyanidins or their derivatives synthesized by the flavonoid pathway. Due to pigments, the NCC has excellent ultraviolet protection properties. Some brown cotton varieties exhibited superior thermal resistance of fiber that can be used to make fabrics with enhanced flame retardancy. Here, we review molecular mechanisms involved in the pigment production of brown cotton and challenges in breeding NCC varieties with a wide range of colors but without penalty in fiber quality. Also, we discuss opportunities for NCC with flame-retarding properties in textile applications.

The functions of laccase gene GhLAC15 in fiber colouration and development in brown-colored cotton.

The monotonicity of color type in naturally colored cottons (NCCs) has become the main limiting factor to their widespread use, simultaneously coexisting with poor fiber quality. The synchronous improvement of fiber quality and color become more urgent and crucial as the demand for sustainable development increases. The homologous gene of wild cotton Gossypium stocksii LAC15 in G. hirsutum, GhLAC15, was also dominantly expressed in the developing fibers of brown cotton XC20 from 5 DPA (day post anthesis) to 25 DPA, especially at the secondary cell wall thickening stage (20 DPA and 25 DPA). In XC20 plants with downregulated GhLAC15 (GhLAC15i), a remarkable reduction in proanthocyanidins (PAs) and lignin contents was observed. Some of the key genes in the phenylpropane and flavonoid biosynthesis pathway were down-regulated in GhLAC15i plants. Notably, the fiber length of GhLAC15i plants showed an obvious increase and the fiber color was lightened. Moreover, we found that the thickness of cotton fiber cell wall was decreased in GhLAC15i plants and the fiber surface became smoother compared to that of WT. Taken together, this study revealed that GhLAC15 played an important role in PAs and lignin biosynthesis in naturally colored cotton fibers. It might mediate fiber color and fiber quality by catalyzing PAs oxidation and lignin polymerization, ultimately regulating fiber colouration and development.

Flavanone and flavonoid hydroxylase genes regulate fiber color formation in naturally colored cotton

Using naturally colored cotton (NCC) can eliminate dyeing, printing and industrial processing, and reduce sewage discharge and energy consumption. Proanthocyanidins (PAs), the primary coloration components in brown fibers, are polyphenols formed by oligomers or polymers of flavan-3-ol units derived from anthocyanidins. Three essential structural genes for flavanone and flavonoid hydroxylation encoding flavanone-3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′5′-hydroxylase (F3′5′H) are initially committed in the flavonoid biosynthesis pathway to produce common precursors. The three genes were all expressed predominantly in developing fibers of NCCs, and their expression patterns varied temporally and spatially among NCC varieties. In GhF3Hi, GhF3′Hi and GhF3′5′Hi silenced lines of NCC varieties XC20 and ZX1, the expression level of the three genes decreased in developing cotton fiber, negatively correlated with anthocyanidin content and fiber color depth. Fiber color depth and type in RNAi lines changed with endogenous gene silencing efficiency and expression pattern,the three hydroxylase genes functioned in fiber color formation. GhF3H showed functional differentiation among NCC varieties and GhF3′H acted in the accumulation of anthocyanin in fiber. Compared with GhF3′H, GhF3′5′H was expressed more highly in brown fiber with a longer duration of expression and caused lighter color of fibers in GhF3′5′H silenced lines. These three genes regulating fiber color depth and type could be used to improve these traits by genetic manipulation.

Transcriptome Co-expression Network and Metabolome Analysis Identifies Key Genes and Regulators of Proanthocyanidins Biosynthesis in Brown Cotton.

Brown cotton fiber (BCF) is a unique raw material of naturally colored cotton (NCC). But characteristics of the regulatory gene network and metabolic components related to the proanthocyanidins biosynthesis pathway at various stages of its fiber development remain unclear. Here, the dynamic changes in proanthocyanidins biosynthesis components and transcripts in the BCF variety “Zong 1-61” and its white near-isogenic lines (NILs) “RT” were characterized at five fiber developmental stages (0, 5, 10, 15, and 20 days post-anthesis; DPA). Enrichment analysis of differentially expressed genes (DEGs), comparison of metabolome differences, and pathway enrichment analysis of a weighted gene correlation network analysis together revealed the dominant gene expression of flavonoid biosynthesis (FB), phenylpropanoid metabolisms, and some carbohydrate metabolisms at 15 or 20 DPA than white cotton. Eventually, 63 genes were identified from five modules putatively related to FB. Three R2R3-MYB and two bHLH transcription factors were predicted as the core genes. Further, GhANS, GhANR1, and GhUFGT2 were preliminarily regulated by GhMYB46, GhMYB6, and GhMYB3, respectively, according to yeast one-hybrid assays in vitro. Our findings provide an important transcriptional regulatory network of proanthocyanidins biosynthesis pathway and dynamic flavonoid metabolism profiles.

Breeding Next-Generation Naturally Colored Cotton.

Use of naturally colored cotton (NCC) in the textile industry is limited due to its inferior fiber quality. Recent advances in understanding pigmentation in NCC fiber and the genetic relationship between pigmentation and fiber development may overcome this hindrance and can guide developing high fiber quality and yield NCC.

Phenylpropanoid metabolism and pigmentation show divergent patterns between brown color and green color cottons as revealed by metabolic and gene expression analyses

BackgroundNaturally-colored cotton has become increasingly popular because of their natural properties of coloration, UV protection, flame retardant, antibacterial activity and mildew resistance. But poor fiber quality and limited color choices are two key issues that have restricted the cultivation of naturally-colored cotton. To identify the possible pathways participating in fiber pigmentation in naturally-colored cottons, five colored cotton accessions in three different color types (with green, brown and white fiber) were chosen for a comprehensive analysis of phenylpropanoid metabolism during fiber development.ResultsThe expression levels of flavonoid biosynthesis pathway genes in brown cotton fibers were significantly higher than those in white and green cotton fibers. Total flavonoids and proanthocyanidin were higher in brown cotton fibers relative to those in white and green cotton fibers, which suggested that the flavonoid biosynthesis pathway might not participate in the pigmentation of green cotton fibers. Further expression analysis indicated that the genes encoding enzymes for the synthesis of caffeic acid derivatives, lignin and lignan were activated in the developing fibers of the green cotton at 10 and 15 days post-anthesis.ConclusionsOur results strengthen the understanding of phenylpropanoid metabolism and pigmentation in green and brown cotton fibers, and may improve the breeding of naturally-colored cottons.

ESTIMATES OF GENETIC PARAMETERS FOR SELECTION OF COLORED COTTON FIBER1

ABSTRACT Naturally-colored cotton fiber has received attention from breeding programs in the semiarid region of northeastern Brazil due to an increased interest in its fibers. Therefore, this study aimed to select genotypes of colored cotton fiber for agronomic and technological fiber characteristics for the Brazilian semi-arid conditions. The experiment was carried out in two environments (Patos-PB and Apodi-RN) in Brazil during the 2016 growing season. The experimental design was in randomized blocks with four replications. Treatments consisted of eleven colored fiber genotypes and three controls (BRS Topázio, BRS Rubi, and BRS Verde). The following traits were assessed: seed cotton yield (SCY, kg ha-1), lint percentage (LP, %), lint length (LEN, mm), lint strength (STR, gf tex-1), and lint micronaire (MIC, µg in-1). The data were submitted to individual and joint variance analyses, and means were grouped by the Scott and Knott (1974) test at 0.05 probability. Genotypes showed variability in all traits, which allows genetic gains in subsequent cycles of selection. The genotypes BRS Topázio, CNPA 2002 10245, and CNPA 2002 10327 presented the best estimates for the assessed traits, thus they can be selected for future studies in cotton breeding programs in the semiarid region.

Physicochemical characterization of several types of naturally colored cotton fibers from Peru

Elemental composition, physical dimensions (length and apparent diameter), and crystallinity of different types of naturally colored cotton (NCCs) fibers from Peru were investigated using a CHNS organic elemental analyzer, optical microscopy and X-Ray Diffraction (XRD). Spectroscopic studies involving Fourier Transform Infrared Spectroscopy and X-Ray photoelectron spectroscopy (XPS) were conducted; and the thermal stability of cotton samples were also investigated. Results from organic elemental analyzer and XPS showed that cotton samples contain mainly carbon, oxygen and hydrogen, but darker color samples also presented nitrogen. It was also found that the white cotton sample exhibited the longest fibers whereas the darker color samples showed the shortest values in length. Interestingly, the crystallinity seems also decrease with color intensity of NCCs. Finally, the thermal stability of white cotton fibers was similar to those obtained for the NCCs.

Physiology and production of naturally-colored cotton under irrigation strategies using salinized water

Abstract: The objective of this work was to evaluate the effects of irrigation management strategies, using low (0.8 dS m-1) and high (9.0 dS m-1) salinity water, on the physiological processes, production variables, and fiber productivity of naturally-colored cotton (Gossypium hirsutum) genotypes during different phenological stages. Three naturally-colored cotton cultivars (BRS Rubi, BRS Topázio, and BRS Safira) were subjected to seven irrigation management strategies, in a 3x7 factorial arrangement, in a randomized complete block design with three replicates. Plants were cultivated in pots in a protected environment. Gas exchange, chlorophyll a fluorescence, fiber production, and productivity and yield variables were evaluated. Salt stress causes greater reductions in gas exchange in natural cotton plants during the production stage. Plume cotton production is not compromised by the use of highly salinized water during the initial developmental stages of naturally-colored cotton.

Construction of the Morphological Structure Model of Overground Part of Naturally-Colored Cotton in Alaer Reclamation Area in Xinjiang

Construction of the Morphological Structure Model of Overground Part of Naturally-Colored Cotton in Alaer Reclamation Area in Xinjiang

Quantitative Analysis of Naturally Colored Cotton and White Cotton Blends by UV–VIS Diffuse Reflectance Spectroscopy

A new method was discussed to quantitatively analyze the blend ratio of naturally colored cotton (NCC) and white cotton (WC) by UV–vis diffuse reflectance spectroscopy (UV–vis DRS). Three kinds of spectroscopy parameters, diffuse reflectance, reflection absorbance, and the K–M function, were used to correlate them with the blend ratio of NCC/ WC fibers. The results showed that diffuse reflectance and blending ratio had the highest correlation coefficients. Therefore this method can be widely used to quantify the blending ratio of NCC/WC fibers as a result of its greater accuracy and simplicity compared to traditional detection methods.

Analysis of antibacterial properties of naturally colored cottons

The antibacterial activity of naturally colored cottons (NCCs) is evaluated. Compared to the conventional white cotton, brown NCC was found to exhibit excellent antibacterial activity with a reduction rate of 89.1% and 96.7%, when in contact with two species of bacteria, Staphylococcus aureus and Klebsiella pneumoniae, respectively, while the antibacterial effect of green NCC was faint. To investigate the antibacterial mechanism of NCCs, pigments have been extracted from NCC fibers for further determination of their antibacterial activity using the disk diffusion method, and the chemical nature of extracted pigments was also analyzed. The results are as follows: the pigment from brown cotton fibers showed significant inhibition against the two challenge bacteria, while the resistance capacity of the pigment from green cotton fiber was insignificant, indicating that the antibacterial efficacy of NCC fibers was highly related to the chemical nature of the pigment. Diagnostic results indicated that the pigment from brown cotton belonged to condensed tannins, and the pigment from green cotton fiber was identified as flavonoids. The effect of high-temperature treatment on antibacterial activity of the pigment extracted from brown cotton was also examined. It showed that the general textile high-temperature curing conditions decrease its antibacterial activity, but the antibacterial activity still has a satisfactory retention, indicating a durable natural antibacterial performance of brown NCC to the high-temperature curing technology.

Within-plant distribution of cotton aphid (Hemiptera: Aphididae) in cotton cultivars with colored fibers

We describe the vertical and horizontal distribution of the cotton aphid Aphis gossypii Glover within a cotton plant in two cotton (Gossypium hirsutum Linnaeus) cultivars (BRS Safira and BRS Rubí) with colored fiber over the time. Measurements of aphid population dynamics and distribution in the cotton plants were recorded in intervals of seven days. The number of apterous or alate aphids and their specific locations were recorded, using as a reference point the location of nodes on the mainstem of the plant and also those on the leaves present on branches and fruit structures. The number of apterous aphids found on the cultivar BRS Safira (56,515 aphids) was greater than that found on BRS Rubí (50,537 aphids). There was no significant difference between the number of alate aphids found on the cultivars BRS Safira (365 aphids/plant) and BRS Rubí (477 aphids/plant). There were interactions between cotton cultivar and plant age, between plant region and plant age, and between cultivar and plant region for apterous aphids. The results of this study are of great importance in improving control strategies for A. gossypii in the naturally-colored cotton cultivars BRS Safira and BRS Rubí.

Effect of Laundering Temperature on the Color of Brown Naturally Colored Cotton

The color performance properties of brown naturally color cotton fabric was investigated in the elevated temperature home laundering, usually the Europe style laundering. The first laundering cycle would give naturally color cotton(NCC) fabric the most of color changes. The laundering did render NCC fabric darkening effect, and significant and proceeding color changes. The higher laundering temperature resulted in more color changes of the fabric. At least 0.5 class gray scale rating was increased for about per 30°C laundering temperature increase. The data reported here indicated that lower temperture home laundering benefit the color retentation and the care of the NCC fabric.

The Effects of 1,2,3,4-Butanetetracarboxylic Acid (BTCA) Finishing on the Color of Naturally Colored Cotton Fabrics

Naturally colored cotton (NCC) based wovens are finished with 1,2,3,4-butanetetracarboxylic acid (BTCA), which is an environmentally friendly durable press (DP) finish. The colors of the NCC wovens before and after DP finishing are examined. The color fastnesses to home laundering and light irradiation are compared and evaluated. The DP finishing of BTCA has a negative effect on the color of NCC based fabrics. About 1/3 of the shade depth of the NCCs are decreased after a BTCA finishing. For both the fabrics with and without a DP finishing, home laundering results in evident color changes with decrease of shade depth. However, for probable crosslinking to pigments, a DP finishing could significantly improve the home laundering color fastness of NCCs. The performance of the color fastness to light after a BTCA finishing depends on the cotton breed. The BTCA finishing of the green NCC minimally improves the light fastness, while for the brown NCC, the color fastness to light decreases after the BTCA finishing.