## 5 Biological Activities of Rice Phytolexins
### Bioactivities of Diterpeneoid Phytolexins
\begin{table}
\begin{tabular}{l l l} \hline
**Metabolite/s** & **Activity** & **Experimental Model** & **References** \\ \hline  & & Elicitation of momilactone accumulation and secretion in \(C\). \\  & _plumiforme_ through UV, jasmonic acid, metals (CuCl\({}_{2}\) and FeCl\({}_{2}\)), and a protein phosphatase inhibitor (cantharidin). \\ \hline  & Evaluation of inhibitory activity of H\({}_{2}\)O:MeOH extracts of soil under colonies of \(C\). _plumiforme_ on growth of creess (_Lepidium sativum_), lettuce (_Lactuca sativa_), lucure (_Medicago sativa_), ryegrass (_Lolium multiformu_), timothy (_Phleum pratense_), _Digitaria sanguinalis_, and _Echinochla crus-galli_. \\ \hline  & Evaluation of inhibitory activity of momilactones A and B from root exudates of rice (cv. Koshihikari) on growth of barnyard grass (length of shoot and hypocotyl). Evaluation of allebotathic activity of six rice cvs. (Hinohikari, Kamenoo, Kinuhikari, Koshihikari, Nipponbare, Norin 8, Sasanishishiki, and Yukihikari) by donor-receiver bioassay. \\ \hline  & Evaluation of momilactone B production and release in rice (\(O\). _sativa_) and barnyard grass (_E. crus-galli_) co-cultures. \\ \hline  & Screening of 41 different rice cvs. for their ability to reduce germination, root growth, and root dry weight of _Alsima_ \\  & _plantago-aquatica_. Quantification of momilactone B in the studied rice cvs. \\ \hline  & Evaluation of allebotathic activities of momilactones A and B from husks of rice (cv. Koshihikari) against different plant species, including nine weed species [Cress, lettuce, alfalfa (_Medicago sativa_), ryegrass (_Lolium multiformu_), timothy, barnyard grass, _Echinochla colonum_, crabgrass (_Digitaria sanguinalis_), and _Arabidopsis thaliana_], and four rice cvs. (Koshihikari, Nipponbare, Norin 8, and Sasanishiki). \\ \hline  & Evaluation of allebotathic activity of barnyard grass in response to momilactone B from rice (cv. Koshihikari) seedlings or root exudates. \\ \hline  & Evaluation of inhibitory activity of momilactones A, B, E from rice (cv. Koshihikari) husk on germination rate and root and shoot elongation of lettuce, barnyard grass, and tall goldenrod (_Solidago altissima_). \\ \hline  & Evaluation of cytotoxic activity of momilactones A and B from rice (cv. Hochokjindo) hulls against P388 murine leukemia cells. \\ \hline  & Evaluation of cytotoxic and antitumor activity of methanolic extract and momilactone B from rice hulls by MTT-dye reduction assay against human colon cancer cells and colonic aberrant crypt foci (ACF) assay in 1,2-dimethylhydrazine (DMH)-injected F344 male rats, respectively. \\ \hline  & Investigation of the molecular mechanism responsible for the inhibitory effects of momilactone B on the growth of cultured human breast cancer T47D cells. \\ \hline  & Evaluation of antitumor efficacy by inducing apoptosis in several mammalian blood cancer cells, including human leukemic T cells. \\ \hline  & Investigation of the molecular mechanism responsible for the inhibitory effects of momilactone B on cultured human leukemia \\ \hline  & Investigation of the molecular mechanism responsible for the cytotoxic activity of momilactones A and B against multiple myeloma \\ \hline  & U266 and acute promylocytic leukemia HL-60 cell lines. \\ \hline  & & \\ \end{tabular}
\end{table} 
Table 4: _Cont._  
\begin{table}
\begin{tabular}{l l l} \hline
**Metabolite/s** & **Activity** & **Experimental Model** & **References** \\ \hline \multirow{6}{*}{Increased tolerance to salinity and drought stresses} & Correlation between the content of momilactones A and B and tolerance to salinity and drought in 30 rice cultivars. & [177] \\ \cline{2-3}  & \multirow{2}{*}{Increased tolerance to salinity and drought stresses} & Induction of momilactones A and B by application of exogenous vanillic acid and \(p\)-hydroxybenzoic acid to two rice cvs., one drought-tolerant (Nep nanh ngua Hai phong), and one drought-susceptible rice (Re nuoc).