Exogenous aluminum induced growth inhibition and apoptosis in wheat seedlings

Abstract

Aluminum (Al) toxicity significantly limits plant productivity, hinders plant growth, and reduces food production in most crops, including wheat. The present study explored the effects of AlCl3 on wheat seedlings at the physiological and cytological levels. The results showed that Al-3(+) stress affected chlorophyll synthesis in wheat seedling leaves. We found that chlorophyll content and Al3+ concentration are negatively correlated in wheat seedlings. Root length, number of adventitious roots, and cell division index at the root tip showed a negative correlation with Al3+ concentration. Besides, Al3+ stress caused chromosomal aberrations in wheat seedlings, such as micronuclei and polynuclear formation, chromosomal breakage, the formation of a chromosomal bridge, and chromosomal loop. Exogenous application of excess Al could cause H2O2 accumulation in meristematic and elongation regions of the root, membrane oxidation, programmed cell death, and DNA damage. These results showed that excessive application of exogenous Al inhibited the normal growth of wheat and affected various physiological activities in wheat. Therefore, Al toxicity severely affects the growth and development of wheat seedlings.