Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. Previous studies in mutants have recessive liguleless mutants (lg1 and lg2) and dominant mutations in knotted1-l...

CRISPR-Cas9 technology, which uses an RNA-guided nuclease, has been developed as an efficient and versatile genome-editing method to induce mutations in genes of interest. To examine the feasibility of this method in developmental studies of a model monocot, rice (Oryza sativa), we introduced the construct gDL-1, which produced a guide RNA targeting the DROOPING LEAF (DL) gene. DL regulates mid...

Molecular genetics has been successful in identifying leaf- size regulators such as transcription factors, phytohormones, and signal molecules. Among them, a ROTUNDIFOLIA4-LIKE/DEVIL (RTFL/DVL) family of Arabidopsis, genes encoding peptides with no secretion-signal sequence, is unique in that their overexpressors have a reduced number of leaf cells specifically along the proximodistal axis. How...

Competition for light triggers numerous developmental adaptations known as the "shade-avoidance syndrome" (SAS). Important molecular events underlying specific SAS responses have been identified. However, in natural environments light is often heterogeneous, and it is currently unknown how shading affecting part of a plant leads to local responses. To study this question, we analyzed upwards le...

The role of auxin in controlling leaf expansion remains unclear. Experimental increases to normal auxin levels in expanding leaves have shown conflicting results, with both increases and decreases in leaf growth having been measured. Therefore, the effects of both auxin application and adjustment of endogenous leaf auxin levels on midrib elongation and final leaf size (fresh weight and area) we...

St. Augustinegrass is a widely used turf and pasture grass in the southern US. Raleigh is a cultivar known for superior cold tolerance than other St. Augustinegrass cultivars. However, its coarse-leaf texture and long internodes are undesirable when planted in home lawns. Mutagenesis by gamma ray irradiation was employed to treat node cuttings and calli for inducing semi-dwarf growth phenotype....

The role of alpha-naphthaleneacetic acid (NAA) in the control of abscission in Citrus (Citrus sinensis L. Osbeck) leaf explants and its conjugation were studied in non-aged and 24-hour-aged explants. Dipping non-aged explants in 1.5 micromolar NAA for 15 minutes immediately after excision did not delay abscission whereas 150 micromolar NAA effectively delayed it. As incubation time was prolonge...

Many plants show some form of helical growth, such as the circular searching movements of growing stems and other organs (circumnutation), tendril coiling, leaf and bud reversal (resupination), petal arrangement (contortion) and leaf blade twisting. Recent genetic findings have revealed that such helical growth may be associated with helical arrays of cortical microtubules and of overlying cell...

Leaf decay in seagrasses is enhanced some seasons since large green senescent beach-cast seagrass leaves are frequently recorded during autumn and winter seasons. Here, we explore if senescence operating leaf or hydrodynamic stress responsible for the seasonal abscission. A study on temperate Cymodocea nodosa was carried out four locations with contrasting regimes. The morphological, biomechani...