618 / 2019-04-24 10:13:06

The longevity of shoot apical meristems in clavata3 mutant

Developmental programmed cell death

Growth and Development > Growth and Development

The shoot apical meristem (SAM) maintains stem cell populations in plants. Therefore, proliferative activity of SAM determines the size of plant body. However, molecular mechanisms regulating the longevity of SAM are largely unknown. It was reported that stem cells lost proliferative activities at the end of plant life, resulting from the reduction of expression of the stem-cell-regulator gene WUSCHEL (WUS). WUS expression is repressed by CLAVATA3 (CLV3) ligand. We found that the longevity of clv3-2 mutant was longer than wild type (WT). Consistent with the morphological data, WUS expression was stopped at three WAB in WT, while that was terminated at six WAB in clv3-2. These results indicated that the termination of WUS expression is an indicator for the plant longevity. To clarify whether developmental programmed cell death (dPCD) is induced in SAM at the end of plant life, we checked the spatiotemporal expression patterns of a key gene for PCD, BIFUNCTIONAL NUCLEASE1 (BFN1). We would like to discuss molecular mechanisms regulating the plant longevity.