Tag Archives: kristin beale

Pistil leads pollen in life-and-death dance

Pollination, essential to much of life on earth, requires the explosive death of the male pollen tube in the female ovule. In new research, Brown University scientists describe the genetic and regulatory factors that compel the male’s role in the process. Finding a way to tweak that performance could expand crop cross-breeding possibilities.

PROVIDENCE, R.I. [Brown University] — Millions of times on a spring day there is a dramatic biomolecular tango where the flower, rather than adorning a dancer’s teeth, is the performer. In this dance, the female pistil leads, the male pollen tubes follow, and at the finish, the tubes explode and die. A new paper in Current Biology describes the genetically prescribed dance steps of the pollen tube and how their expression destines the tube for self-sacrifice, allowing flowering plants to reproduce. (more…)

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Pollination with Precision: How Flowers Do It

Pollination could be a chaotic disaster. With hundreds of pollen grains growing long tubes to ovules to deliver their sperm to female gametes, how can a flower ensure that exactly two fertile sperm reach every ovule? In a new study, Brown University biologists report the discovery of how plants optimize the distribution of pollen for successful reproduction.

PROVIDENCE, R.I. [Brown University] — Next Mother’s Day, say it with an evolved model of logistical efficiency — a flower. A new discovery about how nature’s icons of romance manage the distribution of sperm among female gametes with industrial precision helps explain why the delicate beauties have reproduced prolifically enough to dominate the earth.

In pollination, hundreds of sperm-carrying pollen grains stick to the stigma suspended in the middle of a flower and quickly grow a tube down a long shaft called a style toward clusters of ovules, which hold two female sex cells. This could be a chaotic frenzy, but for the plant to succeed, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don’t work. (more…)

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