Cotton (Gossypium hirsutum L.) is considered a drought tolerant crop.
However, tolerance differs greatly across cotton genotypes. Hence, it is
imperative to improve its drought tolerance. A gene from Tamarix
androssowii, an extremely drought tolerant shrub in Xinjiang, China, may
provide us with the solution.

In a previous study, transgenic poplars overexpressing the T. androssowii
gene, TaMnSOD, have showed improved drought tolerance. Based on these
previous studies, TaMnSOD was introduced and then overexpressed in cotton to
create several independent transgenic lines. The transgenic lines and
control plants were evaluated and compared their stress-related
physiological and biochemical parameters under water deficit conditions in a
growth chamber. Morphological traits were also observed after recovery from
water-withholding stress.

Transgenics had improved antioxidant enzyme activity and cell membrane
integrity. Furthermore, net photosynthesis, stomatal conductance, and
transpiration rate were also increased in transgenic plants. Transgenic
cotton also showed increased biomass and root and leaf systems compared to
wild types after 2 weeks recovery from drought stress.

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