Live-Autoradiography Technique Reveals Genetic Variation in the Rate of Fe Uptake by Barley Cultivars

Iron (Fe) is an essential trace element in plants; however, the available Fe in soil solution does not always satisfy the demand of plants. Genetic diversity in the rate of Fe uptake by plants has not been broadly surveyed among plant species or genotypes, although plants have developed various Fe acquisition mechanisms. The live-autoradiography technique with radioactive Fe-59 was adopted to directly evaluate the uptake rate of Fe by barley cultivars from a nutrient solution containing a very low concentration of Fe. The uptake rate of Fe measured by live autoradiography was consistent with the accumulation of Fe-containing proteins on the thylakoid membrane. The results revealed that the ability to acquire Fe from the low-Fe solution was not always the sole determinant of tolerance to Fe deficiency among barley genotypes. The live-autoradiography system visualizes the distribution of beta-ray-emitting nuclides and has flexibility in the shape of the field of view. This technique will strongly support phenotyping with regard to the long-distance transport of nutrient elements in the plant body.

Automated summary

Iron is an essential element for plants, and their ability to acquire iron from low-iron solutions is not the sole determinant of tolerance to iron deficiency among barley genotypes. The live-autoradiography technique can help visualize the distribution of iron in plants and support phenotyping for nutrient transport.