Identification and Functional Characterization of OsSULTR3;1 in Grain Selenium Accumulation in Rice.

Area of Science:

• Plant Biology
• Agricultural Science
• Nutritional Science

Background:

• Rice is a global staple and a significant source of selenium (Se).
• Approximately one billion people worldwide suffer from Se deficiencies.
• Plants utilize sulfate transporters (SULTRs) for the uptake and transport of both sulfur (S) and selenium (Se).

Purpose of the Study:

• To identify rice SULTR genes responsible for selenium accumulation in grains.
• To elucidate the role of specific SULTR genes in plant Se uptake and transport.

Main Methods:

• Analysis of 12 rice SULTR gene expression across various tissues and developmental stages.
• Investigating gene expression under different selenium (Se) and sulfur (S) treatments.
• Utilizing yeast heterologous expression to confirm transporter function.
• Creating and analyzing OsSULTR3;1 overexpression and knockout rice lines.

Main Results:

• OsSULTR3;1 exhibited strong expression in rice grains and was notably induced by Se.
• OsSULTR3;1 facilitated the active uptake of both selenate and selenite forms of Se.
• OsSULTR3;1 knockout lines showed significant reductions in grain Se content (up to 69.6%).
• OsSULTR3;1 overexpression lines demonstrated substantial increases in grain Se content (up to 78.5%).

Conclusions:

• OsSULTR3;1 plays a critical role in regulating Se accumulation in rice grains.
• This gene is a key target for breeding Se-enriched rice varieties.
• Findings offer a pathway to mitigate Se deficiency through dietary staple modification.