A cotton gene encoding a plasma membrane aquaporin is involved in seedling development and in response to drought stress

Abstract

<title>Abstract</title> Cotton (<italic>Gossypium hirsutum</italic>), the most important textile crop worldwide, often encounters abiotic stress such as drought and waterlog during its growth season (summer), and its productivity is significantly limited by adverse factors. To investigate the molecular adaptation mechanisms of this plant species to abiotic stress, a gene encoding the plasma membrane intrinsic protein (PIP) was isolated in cotton, and designated as <italic>GhPIP2;7</italic>. Quantitative reverse transcriptase polymerase chain reaction analysis indicated that <italic>GhPIP2;7</italic> was preferentially expressed in cotyledons and leaves, and its expression was up-regulated in leaves after drought treatments. Strong expression of <italic>GUS</italic> gene driven by <italic>GhPIP2;7</italic> promoter was detected in leaves of 5- to 10-day-old transgenic <italic>Arabidopsis</italic> seedlings, but <italic>GUS</italic> activity gradually became weak as the seedlings further developed. <italic>GhPIP2;7</italic> promoter activity was also remarkably induced by mannitol treatment. Furthermore, yeast cells over-expressing <italic>GhPIP2;7</italic> displayed relatively higher drought tolerance, compared with controls. Over-expression of <italic>GhPIP2;7</italic> in <italic>Arabidopsis</italic> enhanced plant tolerance to drought stress. Collectively, these data suggested that <italic>GhPIP2;7</italic> gene may be involved in leaf development and in response to drought stress.