Research groups at the University of Tsukuba and Okayama University have succeeded in clarifying why rice is resistant to aluminum toxicity.
Aluminum is the most abundant metal element in the crust and elutes when the soil becomes acidic, inhibiting plant growth.Growth inhibition by aluminum is the second largest factor in reducing crop yields in the world after drying, and countermeasures are an urgent issue.
On the other hand, it is known that plants that are resistant to aluminum exist by secreting organic acids that form compounds with aluminum from the roots, but rice has high resistance to aluminum even though organic acid secretion is not functioning effectively. The mechanism has been a mystery.
In this study, we focused on "pectin", a type of cell wall with high aluminum adsorption, which is secreted from the roots of rice.
First, when the relationship between aluminum concentration and pectin secretion was investigated, it was found that in wild-type rice, the higher the aluminum concentration, the more pectin was secreted.However, no increase in pectin secretion was observed in the mutant rice with weak aluminum resistance.
Next, when the relationship between pectin secretion and aluminum adsorption to roots was investigated, in wild-type rice, almost no aluminum adsorption occurred, whereas in mutant rice, aluminum roots were found in many areas. Adsorption was confirmed.From this, it was considered that in rice, pectin acts as a barrier to prevent the adsorption of aluminum to the roots and maintain the aluminum resistance.
Based on this result, the researchers can expect to produce crops that can be cultivated even in acidic soil by applying and introducing a mechanism for alleviating aluminum toxicity by pectin secretion even for crops with weak aluminum resistance. There is.
Paper information:[Frontiers in Plant Science] Changes in the Distribution of Pectin in Root Border Cells Under Aluminum Stress
