The NHX-type cation transporters in plants have been shown to mediate cation
exchange for salinity tolerance and potassium homoeostasis. Yang Zeng of
Nanjing Agricultural University in China identified and characterized two
NHX homologs, HtNHX1 and HtNHX2, from an infertile and salinity tolerant
Jerusalem artichoke (Helianthus tuberosus).

The two genes were then cloned and expressed separately in rice cultivars.
Both hydroponics and soil culture experiments showed that the expression of
HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Moreover,
expression of HtNHX2 increased rice grain yield, harvest index, total
nutrient uptake under potassium-limited, salt-stress or general nutrient
deficiency conditions.

The results provide a novel insight into NHX transporters function in plant
mineral nutrition.

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