Cadmium-induced the Structure Change of Pigment Gland and the Decrease of Gossypol Content in Cottonseed Kernels

  • Ling Li 580 Shengdi Road, Yan'an, Shaanxi, China


The risk of cotton production on arable land contaminated with heavy metals has increased in recent years. Although cotton shows stronger and widespread resistance to heavy metals such as cadmium (Cd) than other major crops. Here, a pot experiment was performed in order to study Cd-induced alterations in seed kernel gossypol content and pigment gland structure at maturity in two transgenic cotton cultivars (ZD-90 and SGK3) and an upland cotton standard genotype (TM-1). The results showed that Cd accumulation in cottonseed kernels increased with increase on Cd levels in the soil. The seed kernel Cd content in plants grown on Cd treated soils was 10-20 times more than the amount in their controls. There was significant difference on Cd accumulation in cottonseed kernels at 400 and 600 μM Cd level. It was higher in SGK3 and ZD-90 than that in TM-1. However, gossypol content in cottonseed kernels was lower in SGK3 or ZD-90 than that in TM-1. There was a negative correlation (r=0.550) between Cd accumulation and gossypol content in cottonseed kernels. The density of cottonseed kernels pigment gland decreased under Cd stress. It is consistent with the change of gossypol content, which decreased under Cd stress. The damage of ZD-90 and SGK3 was much less under Cd stress while TM-1 was the most severely and Cd sensitivity. Further studies are necessary to understand the cause of the decrease in gossypol content under Cd stress.