[FTIR Spectroscopic Characterization of Material Composition in Functional Leaf of Cotton under Stress of Potassium and Boron].

Potassium (K) and boron (B) are essential nutrient elements for plants, and the elements play an important role for plant growth, development and physiological metabolism. Cotton has a higher demand for K and B; K deficiency or B deficiency often occurs in cotton though. To reveal the component changes in functional leaf of cotton under K and B stress and investigate effects on material composition from K and B. A pot experiment was conducted at Huazhong Agricultural University. (1) the characteristic peaks at 1 546.86, 1 438.85, 1 153.39 and 1 024.17 cm(-1) disappeared due to B deficiency, and relative absorbance of other characteristic peaks was decreased compared with normal, which suggested that the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in cotent when lack of K. (2) the relative absorbance of all characteristic peaks was increased in the B-deficient cotton leaves compared with normal, suggesting B deficiency leads to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates because of the hindered transportation. (3) lack of both potassium and boron, induced significant changes to both the locations and relative absorbance of characteristic peaks, and the content of protein, and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped. K deficiency led to the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in content; B deficiency gave rise to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates; the content of protein and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped when K and B were all in short supply.

[FTIR Study of Leaf of Different Cotton Genotypes under Potassium Substitution with Sodium.]

Potassium (K) deficiency affects cotton growth. The substitution effects of sodium (Na) and potassium research have been the focus of attention at home and abroad. The aim of this paper was to study the substitution effects of Na and K on material composition in leaf of two kinds of K-efficiency cotton genotypes (HG103 and LG122) using Fourier to transform infrared (FTIR) spectroscopy. The results showed that: (1) the increment of the relative absorbance of HG103 at peaks 2 960, 2 855 and 2 926 cm-1 were the same with LG122 with addition of Na in deficient K, while at peaks 1 078 and 1 103 cm-1, the increment of HG103 was higher than LG122, indicating that in deficient K, Na could promote the synthesis of carbohydrate, protein and esters, wherein the promoting effect on carbohydrate of HG103 was greater than LG122, while for protein and esters, there has no difference. However, the decrement of the relative absorbance at these five peaks of HG103 was higher than LG122 with addition of Na in adequate K, suggesting that in adequate K, the inhibitory effect of Na on carbohydrate, protein and esters of HG103 was less LG122. (2) the peaks at 1 734 and 1 437 cm-1 disappeared due to K dificiency, when added Na, these peaks did not appear, implying that the structure of amideⅠband and cellulose was broken when lack of K when added Na has no changes.