Phosphorus application reduces aluminum toxicity in two Eucalyptus clones by increasing its accumulation in roots and decreasing its content in leaves

Abstract

Under acidic conditions, aluminum (Al) toxicity is an important factor limiting plant productivity; however, the application of phosphorus (P) might alleviate the toxic effects of Al. In this study, seedlings of two vegetatively propagated Eucalyptus clones, E. grandis × E. urophylla ‘G9’ and E. grandis × E. urophylla ‘DH32-29’were subjected to six treatments (two levels of Al stress and three levels of P). Under excessive Al stress, root Al content was higher, whereas shoot and leaf Al contents were lower with P application than those without P application. Further, Al accumulation was higher in the roots, but lower in the shoots and leaves of G9 than in those of DH32-29. The secretion of organic acids was higher under Al stress than under no Al stress. Further, under Al stress, the roots of G9 secreted more organic acids than those of DH32-29. With an increase in P supply, Al-induced secretion of organic acids from roots decreased. Under Al stress, some enzymes, including PEPC, CS, and IDH, played important roles in organic acid biosynthesis and degradation. Thus, our results indicate that P can reduce Al toxicity via the fixation of elemental Al in roots and restriction of its transport to stems and leaves, although P application cannot promote the secretion of organic acid anions. Further, the higher Al-resistance of G9 might be attributed to the higher Al accumulation in and organic acid anion secretion from roots and the lower levels of Al in leaves.

QTL mapping for aluminum tolerance in RIL population of soybean (Glycine max L.) by RAD sequencing

“…Similar results were also obtained by QTL mapping for Al 3+ tolerance in common bean [68]. Recent research has shown that phosphorus application could reduce aluminum toxicity [69]. Taken together, these results demonstrated that there are some QTLs in the colocalized intervals that may be associated with Al 3+ tolerance and P stress in soybean.…”

Importance of Mineral Nutrition for Mitigating Aluminum Toxicity in Plants on Acidic Soils: Current Status and Opportunities

“…A large number of strategies have been explored to mitigate the Al toxicity in plants to acid soils. Most of the strategies can be divided into two classes: inorganic amendments such as exogenous application of mineral elements including Ca, Mg, P, S, B, and Si and ground oxide/hydroxide [ 111 , 112 , 113 , 114 , 115 , 116 , 117 ] ( Table 4 and Table 5 ) and organic amendments such as organo-mineral fertilizers, plant growth promoting bacteria (PGPB), green waste compost, plant-derived biochars, and their combination with other minerals [ 118 , 119 ] which played a pivotal role in Al toxicity alleviation in plants to acid soils. Conversely, we did not observe considerable existing literatures concerning the role of K, Mn, Zn, and Mo in Al toxicity alleviation in plants though these are essential minerals.…”

IRRIGATION FREQUENCIES FOR Eucalyptus grandis SEEDLINGS

“…The recommendation for twice-a-day irrigation frequency can also be reinforced by the best performance observed for the root dry mass parameter ( Table 2). The more abundant the root system is, the greater the chance of survival of the seedling in the field, regardless of its height, so root dry mass is an important indicator of seedling quality, which is directly related to the survival and initial growth of the seedling (MENDONÇA et al, 2016;TENG et al, 2018). In this context, the greater root dry mass produced in the treatment with frequency of two irrigations per day is evidence of the potential of this water management for the production of eucalyptus seedlings.…”