JCR-Comparative studies on seed protein characteristics in eight lines of two Gossypium species

SINGH Arvinder and KAUR Amanjot

摘要：

[背景] 为了改善作物蛋白质的品质，必须了解不同作物种子蛋白质含量及其组成成分多肽。从棉籽粕中分离的蛋白质具有较高的营养价值，除了作为动物饲料和人类食品外，还被证实有广阔的工业应用前景。当前，印度对棉籽蛋白特性的研究报道相对较少。考虑到棉籽蛋白的重要性，本研究选择了在印度所有主要棉花种植区均种植的印度棉（亚洲棉，Gossypium arboreum L.）和陆地棉（G. hirsutum L.），分析其种籽蛋白特性。

[结果] 亚洲棉(A-基因组)棉籽蛋白含量较低，为19.5%~24.3%；但陆地棉(AD-基因组)的棉籽蛋白含量较高，为21.8%~29.5%。球蛋白在两个棉种中都占主导地位，其次是白蛋白、谷蛋白和醇溶蛋白。亚洲棉/陆地棉中的白蛋白/球蛋白与棉籽蛋白质含量均显著正相关。两个棉种中棉籽蛋白提取物的电泳变化均发生在分子量为22 kDa - 27 kDa的区域，而部分A-基因组的品系与AD-基因组品系的条带模式相似。还首次报道了4种具有二硫键的多肽。观察到白蛋白在两个种系间的电泳图谱上有更多的变化，其次是球蛋白。

[结论] 筛选蛋白质含量低或高的品系，可以筛选优越的多肽组分品系，这些品系对营养和工业用途有重要意义。通过对4个2-S链多肽与其它植物种类的组成和特点的比较，认为它们具有豆球朊相似的性质。A-基因组和AD-基因组在条带模式上的相似性，标志着两者之间存在着密切的进化关系。白蛋白组分可用于棉花品种分化的研究。

关键词：棉花；SDS-PAGE；棉籽蛋白；球蛋白

[Abstract]

Background

In order to achieve the targets aiming at the improvement of protein quality, knowledge regarding seed protein fractions and polypeptides constituting them in different crops is essential. Besides having high nutritional value as animal feed and human food, the protein isolates from cottonseed meal have also been proven promising as industrial raw materials for a number of applications. As far as Indian work on the characterization of cotton seed proteins is concerned, relatively meagre reports are available. Keeping in mind the importance of cotton seed proteins, lines belonging to Gossypium arboreum L. (Indian cotton) and G. hirsutum L. (American cotton) which are grown in all the major cotton growing states in India were selected for analysing their seed protein characteristics.

Results

Whereas G. arboreum (A-genome) lines revealed a lower range of seed protein content i.e. 19.5~24.3%, an upper range (21.8~29.5%) could be observed in lines of G. hirsutum (AD-genome). Globulins represented dominating fraction in both species followed by albumins, glutelins and prolamins. A significant positive correlation between albumins/globulins and seed protein content in G. arboreum /G. hirsutum, respectively, was observed. Intraspecific electrophoretic variation in seed protein extracts was observed in the region of molecular weight 22?kDa - 27?kDa in lines of both the species; however some lines with A-genome showed similarity in banding pattern with AD-genome. Four polypeptides with disulphide-linkages were also reported for the first time. Albumins were observed to reveal more variations in their electrophoretic pattern between the lines of two species followed by globulins.

Conclusion

On the basis of present and previous studies, screening the lines with low or high protein content will lead the selection of lines with superior polypeptide fraction important for nutritional and industrial purposes. On comparing the composition and behaviour of four 2-S linked polypeptides with other plant groups, these were suggested to be legumin-like in nature. The similarity in banding patterns between the lines of A-genome and AD-genome species marked towards the close evolutionary relationship between these two. Albumin fractions on the basis of our results could be taken for cultivar differentiation in cotton crop.

[Keywords]

Gossypium; SDS-PAGE; Seed proteins; Globulins

Journal of Cotton Research. 2019; 2:6

https://doi.org/10.1186/s42397-019-0024-3

https://jcottonres.biomedcentral.com/articles/10.1186/s42397-019-0024-3